Rao,
The ones primarily I know of are
Sound and Vision , Begumpet - Monitor audio, NAD, PSB, Marantz, Quad, Yamaha, Definitive Technology, Roksan and many more
USK, Somajiguda - Denon, Polk Audio, KEF
Vector Systems, Panjagutta - Wharfedale, Denon, Dali, B&W
Soundroom, Banjara Hills - many
Cinebels, Banjara Hills - Jamo, Sherwood, Yamaha
JBL Showroom. Prasads Multiplex - JBL, Harman Kardon, Infinity
Bose Showroom, Somajiguda
There are obvioulsy E-zone, Reliance Digital etc kinda big electronic chains on top of these
Check for the phone numbers of these in
Just Dial - India's No.1 local search engine
You can ping me further if you want any more information
