Please suggest best laptop and shop to buy in chennai?

Well, I checked with a freind and he suggested the following.

Delta peripherals
http://deltapage.com/

or

Sethia Infotech
http://www.sethiainfotech.com/price/

You can compare them on line.
Each has a nice selection but as to the actual computer you should get you are going to have to give us some more information as to what it is you want to do with it because there is a great difference between a gaming machine and one for word processing.