How do I start a commercial radio channel in india?
It is not very easy to start a commercial radio of your own. It is government which identifies and decides the location.. almost like petrol pump. Then government invites tender and distributes licences. For big cities the security mony goes upto 100cr. In my opinion, if you want to start an FM station of your own, then educational or community radio is a better alternative. you can mail on nitak212 at gmail.com (firstname.lastname@example.org) for further information, but you should have deep pockets to start one.
I have set up a number of radio stations
It can be rather daunting at first, trying to compile all the information you need, and understanding the process. You can read further information on how to start up a FM radio station at http://www.themulcher.com/worldwide/index.html
I'm sure that the government in India licenses the radio station frequencies as they do in the US, so they should have a central oversight committee or agency.
Have you tried contacting the local government office to ask them about it?