when u have deleted ur GPRS settings in the cell

You can try the following options..

1) sms < model number> to 58355. Its free.. eg:- NOKIA 2700 Then the corresponding operator (Airtel, bsnl or whatever) will send the settings to your cell

2) Put another sim into ur cell. Remove it and Insert your sim again.. You will have the settings in place..

3) Call the Customer Care and tell them to send the settings..