I am using tata docomo from past 5yrs. And the call quality was good network was good and was very cheap.
But I had shifted my home 6 monts back and now problen arises no network at all. I stay in mumbai. And I am on 16th floor and it shows full network but when I call some one there will be no conversation just the call duration running no sound at all moving here and there for network.bad experience from past 6 months.