I have been using this network since 2 years and there was no change in network and service.whenever I received a call it was dropped due to low signal.these incidents happened almost 50 to 60 times .
So I stopped using this network and change to vodafone
Pros
1) lower price
Cons
1) Network issue
2) call dropped
3) service issue
Friends I would not recommend anyone to use tata docomo sim in your phone.it will create many problems for you. And when you start to using internet the first five minutes will be ok then it would not respone saying that check your internet connection.