This is a new trick and is really working, many of friends are using this.
Make the following settings in the mobile:
Account Name :Tatadocomo (it can be anything)
Homepage: http://divein.tatadocomo.com
Acces Point : TATA.DOCOMO.DIVE.IN
Leave username and password as blank
Proxy address: 10.124.94.7
Proxy port : 8080
Data bearer : GPRS/Packet Data
Authentication Type : Normal
That's it friends now you can enjoy Tata Docomo Unlimited Free GPRS.