At first vodafone has got maximum market share in India. Its world’s 2rd largest telecom operator. Also the overall rates and speed of data is very decent. It is available in almost all circles. It has got 3G in almost all circles. Vodafone call is facility too good and customer care service good they response with client. They are also first to successfully launch 4G in various circle and will coming up other circles as well. I think Airtel is better.