To access unlimited free gprs in bpl mobile network india follow the below steps and configure the following settings in your bpl prepaid mobile.
Free gprs settings and new tricks for BPL Users
A/c name: ur Name
Password: ur Mobile no.
Proxy: 10.0.0.10
Apn: mizone
Port:8080
now try accesing gprs and when you exit the browser you will find no decrease in balance.