I dont know to what extent airtel throttles bandwidth on filesharing sites, but some of my friends indeed get crappy speeds on filesharing sites/networks on airtel, while there are some who get good speeds. You need to check up with people in your neighbourhood about how airtel behaves with filesharing sites.If they do throttle speeds, it'd be best to go for bsnl or cable.Reliance can tend to have issues with billing.