I do not have Tata Indicom Broadband available in my city other wise would have looked no further than Tata.

They have bunch of nice unlimited plans..

They are providing 512 kbps unlimited for Rs. 1850 per month
Also they have 1 mbps unlimited for Rs. 3600 per month, though seems little costly for home user but its affordable considering other options available in market.

At places, I saw it was earlier launched for Rs. 3000 per month for 1 mbps unlimited but now its Rs. 3600 per month.

But Ricky, Airtel's 512 kbps unlimited plan is cheaper than Tata Indicom. It is 1499 per month with rental free, however, they don't have any unlimited plan for 1 mbps.