I will recommend you Airtel Mobile operator only for network as this is the number one operator for its nerwork coverage in all over india. But its charges are not affordable to everyone as its 2G data packs starts from 300rs. for 1GB only. However, its 3G and 4G type of Data packs are so much appreciable. If you have enough money to afford, then go for it.
Apart from these, Customer Service is also best. As Airtel is a Private company, you will be listened by its Customer care executives politely. You will not have to wait to talk with them.
At last, you can enjoy their 3G and 4G services. But at ver high prices. And you can also enjoy their network all over India.