I decided to buy Tata Docomo sim for myself last month. Firstly the sim was supposed to get activated in a day or two but it took 5 days to activate. As soon as it got activated, I could not get any signal inside my house as it is on the lower ground floor. My number was not reachable when somebody used to call me. The internet is very slow and it fluctuates a lot. There is no network coverage in most parts of the city.