I am using tata docomo network since 5 years but service provided by them is not good. I am not satisfied with the range of tata docomo network.
This network doesnot provide range in villages in punjab. Even 2g network doesn't work in villages . Although network in cities is quite good but very poor while in village.
Regular 2g and 3g internet packs are expensive but you can get good internet packs in tata docomo star services.
Talking about internet speed, the speed of internet is average. Downloading speed is good using 3g network but 3g internet packs are expensive to use.This is my Personal experience that I have experienced in past 5 years.