Me and my family have been using Airtel for a long time. Previously, we used to only use it to play childish games online, but as we grew, so did our needs.
I began surfing the internet for homework and what not. Its very often that I do not get the connection, or that the service is not available. And whenever I call their support team, they take a whole 5 minutes to just tell me things I already know like my number and name.
It has also happened a billion times, that I have not been getting the services for a whole week because Airtel was upgrading their system. And guess what? They are charging you for that as well.
Hence, airtel is far from my recommendation. Try it at your own risk.