Siva's blog

Most of the Indian Broadband Providers(ISP’s) follow Fair Usage Policy for its users availing “Unlimited” plan. However there are few range above which the original plan is refrained. This is called “Fair Usage Policy”. Each ISP follows different steps after the Limit is reached(after download limits)
Here is the Bharati Airtel Fair Usage Policy:
* 1 mbps till 100GB, 512 kbps beyond 100GB

* 512 kbps till 100GB, 256 kbps beyond 100GB

* 384 kbps till 75GB, 256 kbps beyond 75GB

* 256 kbps till 50GB, 128 kbps beyond 50GB
While Tata indicom Users losses their connection if they exceed the Fair Usage limit, BSNL users get unmetered usage :)
More info can be found here: http://broadbandforum.in/