I have been using Tata DoCoMo since February, 2011.
I have had many issues with the service
Despite providing all documents, my account was blocked with the reason’all documents not submitted’ . Issue was resolved only after constant follow up and re-submitting the documents again
The online’My account’ facility was not active for me due to various errors. This was corrected only after raising a case online and frequent follow ups.
The DoCoMo network coverage is pathetic. Inside apartments/office the coverage drops to NIL. No action/information even after follow ups. Thankfully, the network is OK at my room.
Unreliable 3G - The 3G speeds provided by DoCoMo is awesome, but only when it is working by grace of god. when you come back from office and want to check FB, you wont get anything despite full signal.
On the plus side-
It has great plans to reduce cost - For 2 weeks I had only Rs. 1.85 . and I still have Rs. 1.85 . I have free 6000 seconds of local calls and free national/local sms pack:)
If I manage to get up @ 5am, I get speeds upto 290kbps+:)
The online recharge is improving slowly but surely.
Hope this helps you decide.
Prepaid rocks:)