I was using Airtel and I used MNP to move to Tatadocomo, but right for beginning the network is very poor and call drop is common feature. When contacted the customer care they said that we have to put a booster as the tower is quite far off and this has to be done at our cost.
Also the problems does not get resolved and they send a message stating the problem as been resolved.
I feel the Tata Docomo is cheating the customer and they provide a poor services and it is quite embarasing to get the call drops and poor connectivity. I suggest to the prospective buyer to go for the vodaphone or airttel which is better service providers.