Updates:
The route timing information on buses from/to HSR sector 2 may not be correct. I rarely use those routes now after switching to BIA-7A and G-2 for my commute to Trinity Circle.
Route Finders
Use any of these route finders to get up to date information on bus routes in Bangalore:
http://www.narasimhadatta.info/bmtc_query.html
http://bmtcroutes.in/
Here's a list of all bus routes I know of from within HSR Layout. There are many more bus routes that pass through Agara and along the ring road adjoining HSR Layout. You can use the airport Volvo buses to travel within city limits (up to Hebbal) at normal Volvo fares (sometime Rs 10 more than normal Volvo fares).
Bus Routes
340A/M: From Parangipalya (HSR sector 2), NIFT, CPWD Quarters, 19th main, HSR Depot, Police Station, Agara, Koramangala last stop, St. John's/Forum (Staples side), Dairy Circle/Christ College, Lakkasandra, Wilson Garden, ShantiNagar/Double Road, Richmong Circle (below flyover), Corporation, Majestic.
Volvo/Marcopolo 340A: Seen occasionally. Follows the same route as 340A/M.
Update: If you are near Mantri Sarovar or HSR BDA complex, there are many Volvos starting out from HSR depot in the mornings (between 7 and 8) to Majestic. They leave the depot near Mantri Sarovar, head to BDA complex signal via ring road, turn right there and go towards Koramangala last stop and St. John's. These buses return to the depot in the evenings with the Depot-25 sign on them. You may also find them using the "Silk Board (via HSR Layout)" or "Agara" boards.
340F: Same route as 340A/M till double road. Morning trips go to Mysore bank and Vidhan Soudha. Other trips go via Richmond bus stop (near Cash pharmacy on residency road), Ashirvadam junction, SBI, Anil Kumble Circle, ShivajiNagar.
340C: Same route as 340A/M till Lakkasandra. Goes towards ISRO Layout via Ashoka pillar, Jayanagar. Low frequency. I don't know if this route still exists. Haven't seen it in a while.
340: Goes to K R Market. Same route as 340A/F till Lakkasandra. Goes straight towards K R Market after that. Rarely seen these days. Route 340 terminates at Agara sometimes. Always check if you want to go to sector 2 on this one.
340K: Starts from SomasundaraPalya, comes to Parangipalya and goes to K R Market following the same route as 340. Low frequency. There's one heading to HSR at about 6:50 pm via Agara.
348F: Starts from Agara depot, comes via CPWD Quarters, NIFT to Parangipalya, towards HSR BDA complex, joins ring road at BDA junction, silk board, Madivala and continues on the same route as 340A/M. Sometimes starts from Parangipalya (HSR 2nd sector). Seen every half an hour in the mornings. There's a regular one at 8:20 am from CPWD quarters. Generally faster at getting to Majestic than 340A/M from ParangiPalya. These days I see this plying without a number (just a Vidhan Soudha board).
There are other 348 series routes that start from MangammanaPalya (near Salarpuria apartments in HSR Sector 7). These buses go via HSR 5th Main to ring road, silk board, Hosur road, Madivala, Dairy circle, Lakkasandra and on to Majestic via same route as 340 A/M.
340S: Starts from Parangipalya. Same route as 340A/M till St. Johns. Goes towards Adugodi on Hosur road via Forum (Raheja Arcade side), Adugodi, Langford road junction (Prestige Elgin), Johnson Market, Vellara junction, St. Patrick's Church, SBI, Bowring Institute/St. Mark's Road, Anil Kumble Circle/MG Road, ShivajiNagar.
141K: CPWD quarters to ShivajiNagar via Agara, Jakkasandra, Koramangala last stop, Sony World Junction, National Games Village, Ejipura junction/VivekNagar, Austin Town, Vellara Junction, ShivajiNagar. Rarely seen. I think there's one trip in the mornings at around 8:30 am and another in the evening.
Volvo BIAS-7: HSR BDA complex, Jakkasandra, Koramangala last stop (1st block), Madivala Market, Forum/Checkpost (Staples side), Dairy cirle/Christ College, Lakkasandra, Wilson Garden, ShantiNagar Bus Station/Double Road, Richmond Bus Stop/Cash Pharmacy, M G Road and on to Bangalore Airport via Hebbal. Hourly service. Usually starts at XX:15 (6:20, 7:20, 8:20 and so on) from HSR.
Volvo BIAS-7A: This is the route I'm using these days to get to my office on Ulsoor road. HSR BDA complex, Jakkasandra, Koramangala last stop (1st block), right via Wipro to Sony World Junction, right towards Domlur via Koramangala inner ring road, Dell, Embassy Golf Links, Hero Honda, left at Domlur to join old airport road, Command Hospital, Trinity Circle, Taj Hotel, Ulsoor Road, Indian Express/GPO, Palace Grounds and on Bangalore Airport via Hebbal. Hourly service. Usually starts on time at XX:40 or XX:50 (6:40 am, 7:40 am, 8:50 am, 9:50 am and so on) from HSR BDA complex. In the return direction, you can get BIA-7A from Trinity Circle at about 4:50 pm 6:00 pm and 7:00 pm. It's hard for them to stick to the schedule though and these buses sometimes get delayed by 15 to 20 minutes on the return trip. These buses pass inner ring road near Dell at around 5:10 pm, 6:15 pm and 7:15 pm in the evenings. Most of them will only stop at the bus stop next to Hero Motors near Dell.
BIAS Volvo typical fares: Rs. 205 to the airport from HSR. Rs. 50 to M G Road from HSR. Rs. 35 to Dell/EGL from HSR.
K-3: HSR BDA complex to Basaveshwaranagar via Koramangala, St. Johns, Dairy Circle, Jayanagar, Basavangudi and Vijayanagar.
K-5: HSR BDA complex to Mallasandra via Jakkasandra, Koramangala Sony World junction, Adugodi, Double road, Malleswaram and Jalahalli.
Depot-25: In the afternoons and evenings you might see some buses with boards displaying "Depot-25" or "Agara Depot". These buses terminate at Agara and go on to the BMTC bus depot near Mantri Sarovar apartments.
BIG-10-2 or G-2: There's a BIG-10 route between Sarjapur and Bridade Road/Mayo Hall that passes through Agara. Route details: Sarjapura, Dommasandra, Kaikondanahalli, Spring Fields Apartments, Iblur, Agara, Jakkasandra, Koramangala last stop, right turn towards Sony World signal, straight to Koramangala depot, National Games Village, Passport Office, 80 ft peripheral road, Lower Agaram Road/Vivek Nagar, right turn to Victoria Road, left to Trinity Church road, Trinity Circle, MG Road, Mayo Hall. These buses start from Mayo hall (near ICICI bank) in the reverse direction. This route is pretty good except for the congestion near Sony World. These days, you can find G-2 running late into the night from Mayo hall (I have used it at around 9 pm).
201 series that you get from Domlur or Trinity Circle go through the Koramangala Water tank bus stop from where you can get 340/A/C/F/M/K/S.
http://bmtcroutes.in/
Google Transit has BMTC routes in it now. Searching for directions in Google Maps give you pretty good BMTC route information. Also found http://bmtcroutes.in/.
Here's a list of all bus routes I know of from within HSR Layout. There are many more bus routes that pass through Agara and along the ring road adjoining HSR Layout. You can use the airport Volvo buses to travel within city limits (up to Hebbal) at normal Volvo fares (sometime Rs 10 more than normal Volvo fares).
Bus Routes
340A/M: From Parangipalya (HSR sector 2), NIFT, CPWD Quarters, 19th main, HSR Depot, Police Station, Agara, Koramangala last stop, St. John's/Forum (Staples side), Dairy Circle/Christ College, Lakkasandra, Wilson Garden, ShantiNagar/Double Road, Richmong Circle (below flyover), Corporation, Majestic.
Volvo/Marcopolo 340A: Seen occasionally. Follows the same route as 340A/M.
Update: If you are near Mantri Sarovar or HSR BDA complex, there are many Volvos starting out from HSR depot in the mornings (between 7 and 8) to Majestic. They leave the depot near Mantri Sarovar, head to BDA complex signal via ring road, turn right there and go towards Koramangala last stop and St. John's. These buses return to the depot in the evenings with the Depot-25 sign on them. You may also find them using the "Silk Board (via HSR Layout)" or "Agara" boards.
340F: Same route as 340A/M till double road. Morning trips go to Mysore bank and Vidhan Soudha. Other trips go via Richmond bus stop (near Cash pharmacy on residency road), Ashirvadam junction, SBI, Anil Kumble Circle, ShivajiNagar.
340C: Same route as 340A/M till Lakkasandra. Goes towards ISRO Layout via Ashoka pillar, Jayanagar. Low frequency. I don't know if this route still exists. Haven't seen it in a while.
340: Goes to K R Market. Same route as 340A/F till Lakkasandra. Goes straight towards K R Market after that. Rarely seen these days. Route 340 terminates at Agara sometimes. Always check if you want to go to sector 2 on this one.
340K: Starts from SomasundaraPalya, comes to Parangipalya and goes to K R Market following the same route as 340. Low frequency. There's one heading to HSR at about 6:50 pm via Agara.
348F: Starts from Agara depot, comes via CPWD Quarters, NIFT to Parangipalya, towards HSR BDA complex, joins ring road at BDA junction, silk board, Madivala and continues on the same route as 340A/M. Sometimes starts from Parangipalya (HSR 2nd sector). Seen every half an hour in the mornings. There's a regular one at 8:20 am from CPWD quarters. Generally faster at getting to Majestic than 340A/M from ParangiPalya. These days I see this plying without a number (just a Vidhan Soudha board).
There are other 348 series routes that start from MangammanaPalya (near Salarpuria apartments in HSR Sector 7). These buses go via HSR 5th Main to ring road, silk board, Hosur road, Madivala, Dairy circle, Lakkasandra and on to Majestic via same route as 340 A/M.
340S: Starts from Parangipalya. Same route as 340A/M till St. Johns. Goes towards Adugodi on Hosur road via Forum (Raheja Arcade side), Adugodi, Langford road junction (Prestige Elgin), Johnson Market, Vellara junction, St. Patrick's Church, SBI, Bowring Institute/St. Mark's Road, Anil Kumble Circle/MG Road, ShivajiNagar.
141K: CPWD quarters to ShivajiNagar via Agara, Jakkasandra, Koramangala last stop, Sony World Junction, National Games Village, Ejipura junction/VivekNagar, Austin Town, Vellara Junction, ShivajiNagar. Rarely seen. I think there's one trip in the mornings at around 8:30 am and another in the evening.
Volvo BIAS-7: HSR BDA complex, Jakkasandra, Koramangala last stop (1st block), Madivala Market, Forum/Checkpost (Staples side), Dairy cirle/Christ College, Lakkasandra, Wilson Garden, ShantiNagar Bus Station/Double Road, Richmond Bus Stop/Cash Pharmacy, M G Road and on to Bangalore Airport via Hebbal. Hourly service. Usually starts at XX:15 (6:20, 7:20, 8:20 and so on) from HSR.
Volvo BIAS-7A: This is the route I'm using these days to get to my office on Ulsoor road. HSR BDA complex, Jakkasandra, Koramangala last stop (1st block), right via Wipro to Sony World Junction, right towards Domlur via Koramangala inner ring road, Dell, Embassy Golf Links, Hero Honda, left at Domlur to join old airport road, Command Hospital, Trinity Circle, Taj Hotel, Ulsoor Road, Indian Express/GPO, Palace Grounds and on Bangalore Airport via Hebbal. Hourly service. Usually starts on time at XX:40 or XX:50 (6:40 am, 7:40 am, 8:50 am, 9:50 am and so on) from HSR BDA complex. In the return direction, you can get BIA-7A from Trinity Circle at about 4:50 pm 6:00 pm and 7:00 pm. It's hard for them to stick to the schedule though and these buses sometimes get delayed by 15 to 20 minutes on the return trip. These buses pass inner ring road near Dell at around 5:10 pm, 6:15 pm and 7:15 pm in the evenings. Most of them will only stop at the bus stop next to Hero Motors near Dell.
BIAS Volvo typical fares: Rs. 205 to the airport from HSR. Rs. 50 to M G Road from HSR. Rs. 35 to Dell/EGL from HSR.
K-3: HSR BDA complex to Basaveshwaranagar via Koramangala, St. Johns, Dairy Circle, Jayanagar, Basavangudi and Vijayanagar.
K-5: HSR BDA complex to Mallasandra via Jakkasandra, Koramangala Sony World junction, Adugodi, Double road, Malleswaram and Jalahalli.
Depot-25: In the afternoons and evenings you might see some buses with boards displaying "Depot-25" or "Agara Depot". These buses terminate at Agara and go on to the BMTC bus depot near Mantri Sarovar apartments.
Silk Board (Via HSR Layout): Commonly seen in the evenings along ring road (BTM, Jayadeva side). The board is misleading. They don't terminate at Silk Board. These buses terminate at the BMTC depot near Mantri Sarovar.
CPWD Qaurters: There are some services from/to CPWD quarters without route numbers. Usually seen in the mornings and evenings. These go to Vidhan Soudha and roughly follow the route taken by 340F in the mornings.
Other options from Agara and Ring Road
342 series (Market/Majestic/ShivajiNagar to Sarjapur and surroundings), 341 series (Market/Majestic/ShivajiNagar to Bellandur, Haralur and surroundings) touch Agara. These go via Jakkasandra, Koramangala last stop, Madivala checkpost, Dairy circle/Christ College.
Volvo 500N: Comes from Vijayanagar via Dairy circle, Forum (Staples side), St. John's, Koramangala last stop (1st block), Jakkasandra, Agara and heads to ITPL via ring road.
500 series ply on the ring road and are available from various bus stops adjoining HSR Layout (Silk board, BDA junction, Agara). There are Volvo buses on these routes (500 A and 500 D: Banadshankari/Silk board to Hebbal), 500K, C, L (Vijaynagar, Silk board to ITPL via ring road).
BIAS 8: Electronics City to Bangalore Airport via Silk board, Agara, Marathahalli, K R Puram railway station, Ramamurthy Nagar junction to Hebbal and airport. If you are heading to the airport, BIA-7 and BIA-7A reach faster since the ring road is as congested as the inner city areas these days.
CPWD Qaurters: There are some services from/to CPWD quarters without route numbers. Usually seen in the mornings and evenings. These go to Vidhan Soudha and roughly follow the route taken by 340F in the mornings.
Other options from Agara and Ring Road
342 series (Market/Majestic/ShivajiNagar to Sarjapur and surroundings), 341 series (Market/Majestic/ShivajiNagar to Bellandur, Haralur and surroundings) touch Agara. These go via Jakkasandra, Koramangala last stop, Madivala checkpost, Dairy circle/Christ College.
Volvo 500N: Comes from Vijayanagar via Dairy circle, Forum (Staples side), St. John's, Koramangala last stop (1st block), Jakkasandra, Agara and heads to ITPL via ring road.
500 series ply on the ring road and are available from various bus stops adjoining HSR Layout (Silk board, BDA junction, Agara). There are Volvo buses on these routes (500 A and 500 D: Banadshankari/Silk board to Hebbal), 500K, C, L (Vijaynagar, Silk board to ITPL via ring road).
BIAS 8: Electronics City to Bangalore Airport via Silk board, Agara, Marathahalli, K R Puram railway station, Ramamurthy Nagar junction to Hebbal and airport. If you are heading to the airport, BIA-7 and BIA-7A reach faster since the ring road is as congested as the inner city areas these days.
BIAS 8A: terminates at BTM instead of Electronics City.
BIG-10-2 or G-2: There's a BIG-10 route between Sarjapur and Bridade Road/Mayo Hall that passes through Agara. Route details: Sarjapura, Dommasandra, Kaikondanahalli, Spring Fields Apartments, Iblur, Agara, Jakkasandra, Koramangala last stop, right turn towards Sony World signal, straight to Koramangala depot, National Games Village, Passport Office, 80 ft peripheral road, Lower Agaram Road/Vivek Nagar, right turn to Victoria Road, left to Trinity Church road, Trinity Circle, MG Road, Mayo Hall. These buses start from Mayo hall (near ICICI bank) in the reverse direction. This route is pretty good except for the congestion near Sony World. These days, you can find G-2 running late into the night from Mayo hall (I have used it at around 9 pm).
Here's how to get to some locations from HSR
Majestic/Double Road: 340A/M, 348F - direct route. 340F: Go up to double road and change to any Majestic bus. 340/340K/340C: Go up to Lakkasandra and change to any Majestic bus. BIAS 7 from BDA complex (till Double Road). 348 series from sector 6/7.
Market, Lalbaugh, Kalasipalya: 340/340K go direct. Otherwise use any bus to Agara and switch from there. There are [lenty of buses from Bellandur/Sarjapur road (341, 342 series) that go to Market. You can also go up to Lakkasandra and change from there. Don't wait for the direct bus to these places since they are rare.
ShivajiNagar, St. Mark's road, Richmond, Residency Road, MG Road side: 340F/S are the direct routes (morning trip goes via Vidhan Soudha though). Don't wait specifically for these routes if you see a 340 A/M ready to go. Go up to Double Road on 340A/M and change to ShivajiNagar buses (13, 20, 27, 34, 210 etc.) from there. Another option is to switch at Madivala to the Big-10 bus from Electronics city (G-3) that goes to St. Patrick's Church (near Brigade road).
Mayo hall, Manipal Center, Taj hotel/Lido: BIAS 7A goes to Trinity circle and gets there in about half an hour to 45 minutes. Other option is to go towards Double road, change to ShivajiNagar buses (13, 20, 34, 210) to Richmond bus stop (just after the double road flyover) and change to bus numbers between 304 and 319 to get to Lido mall.
Dell/EGL/Domlur/Inner ring road/Indiranagar side: BIAS-7A goes to Domlur. Another option is to take any 340 series bus to Madivala/Koramangala water tank and change to 201 series from there (some 201 series buses turn left at Sony World, always check). Yet another option is to change to 171 series from Koramangala last stop and change again to 201 series at Sukh Sagar/Sony World.
ITPL/Ring road towards Marathahalli: Get to Agara and change to 500 series buses from there.
Sarjapur road/Wipro corporate office: 342 series/G-2 from Agara.
Electronics-city/Bommanahalli: Get to Agara and use 500 series to get to silk board. Walk on to hosur road and get 356, 360 series from there. BIAS-8 and 505 passing via Agara go directly.
BTM/Jayanagar/Mysore road side: Change to 500 series from Agara. Many of them go up to Banashankari bus station passing through BTM, Jayadeva.
Getting to HSRWhen you need to get to HSR layout, the best approach is to first get to major bus stops like St. John's or Agara that have many routes passing through them. This increases your chances of getting a bus that goes all the way to HSR layout. All 340 series buses to HSR pass through St. John's, so it's a good changeover point. Route numbers between 340 and 362 pass through St. John's. All routes from 340 to 342 from St. John's pass through Agara. There are also some buses to Sarjapur that start from St. John's.
Majestic/Double Road: 340A/M, 348F - direct route. 340F: Go up to double road and change to any Majestic bus. 340/340K/340C: Go up to Lakkasandra and change to any Majestic bus. BIAS 7 from BDA complex (till Double Road). 348 series from sector 6/7.
Market, Lalbaugh, Kalasipalya: 340/340K go direct. Otherwise use any bus to Agara and switch from there. There are [lenty of buses from Bellandur/Sarjapur road (341, 342 series) that go to Market. You can also go up to Lakkasandra and change from there. Don't wait for the direct bus to these places since they are rare.
ShivajiNagar, St. Mark's road, Richmond, Residency Road, MG Road side: 340F/S are the direct routes (morning trip goes via Vidhan Soudha though). Don't wait specifically for these routes if you see a 340 A/M ready to go. Go up to Double Road on 340A/M and change to ShivajiNagar buses (13, 20, 27, 34, 210 etc.) from there. Another option is to switch at Madivala to the Big-10 bus from Electronics city (G-3) that goes to St. Patrick's Church (near Brigade road).
Mayo hall, Manipal Center, Taj hotel/Lido: BIAS 7A goes to Trinity circle and gets there in about half an hour to 45 minutes. Other option is to go towards Double road, change to ShivajiNagar buses (13, 20, 34, 210) to Richmond bus stop (just after the double road flyover) and change to bus numbers between 304 and 319 to get to Lido mall.
Dell/EGL/Domlur/Inner ring road/Indiranagar side: BIAS-7A goes to Domlur. Another option is to take any 340 series bus to Madivala/Koramangala water tank and change to 201 series from there (some 201 series buses turn left at Sony World, always check). Yet another option is to change to 171 series from Koramangala last stop and change again to 201 series at Sukh Sagar/Sony World.
ITPL/Ring road towards Marathahalli: Get to Agara and change to 500 series buses from there.
Sarjapur road/Wipro corporate office: 342 series/G-2 from Agara.
Electronics-city/Bommanahalli: Get to Agara and use 500 series to get to silk board. Walk on to hosur road and get 356, 360 series from there. BIAS-8 and 505 passing via Agara go directly.
BTM/Jayanagar/Mysore road side: Change to 500 series from Agara. Many of them go up to Banashankari bus station passing through BTM, Jayadeva.
Getting to HSRWhen you need to get to HSR layout, the best approach is to first get to major bus stops like St. John's or Agara that have many routes passing through them. This increases your chances of getting a bus that goes all the way to HSR layout. All 340 series buses to HSR pass through St. John's, so it's a good changeover point. Route numbers between 340 and 362 pass through St. John's. All routes from 340 to 342 from St. John's pass through Agara. There are also some buses to Sarjapur that start from St. John's.
G-3 buses starting from Brigade road touch St. John's. These buses are very frequent in the evenings.
201 series that you get from Domlur or Trinity Circle go through the Koramangala Water tank bus stop from where you can get 340/A/C/F/M/K/S.
If you are in ShivajiNagar bus station and don't see 340F or 340S there don't wait for them. Get on to a route like 362C or 342 to get to St. John's or Agara. If you don't find any routes between 340 and 362 at Shivajinagar, use 13, 20, 34, 37 or 365 series to ShantiNagar/Double road from where you'll get plenty of buses (340 to 360) that will go to St. John's. At St. John's you'll get any of 340/A/C/F/M/K/S to HSR.
Changing multiple buses like this often gets you home faster when compared to waiting for a direct bus (using direction based routes instead of specific destination based routes). Having a daily pass is very convenient if you need to switch between multiple buses. Daily passes cost Rs. 45 (Rs. 40 if you buy a BMTC identity card for Rs. 25) and can be used on any BMTC bus expect the Volvo services. BIG-10 buses also accept daily passes. Volvo buses have a daily pass available for Rs. 90. These passes can be used on all services except the BIA buses. Month pass charges range from about Rs 660 for ordinary buses to Rs. 1300 for Volvo buses.
Changing multiple buses like this often gets you home faster when compared to waiting for a direct bus (using direction based routes instead of specific destination based routes). Having a daily pass is very convenient if you need to switch between multiple buses. Daily passes cost Rs. 45 (Rs. 40 if you buy a BMTC identity card for Rs. 25) and can be used on any BMTC bus expect the Volvo services. BIG-10 buses also accept daily passes. Volvo buses have a daily pass available for Rs. 90. These passes can be used on all services except the BIA buses. Month pass charges range from about Rs 660 for ordinary buses to Rs. 1300 for Volvo buses.
I'll update this with maps when I find the time.