here is the trick for free sms exclusively for airtel.
change your message centre no. to +919898051916
and send sms via gprs
or in some mobiles it is like use PACKET DATA.
and in settings make gprs always available.
when G IS AVAILABLE then you can send free sms.
also make delivary report off if you want to send multiple messages.
otherwise it will cost you.
enjoyyyyyyyyyyyyyyyyy.
Reliance Hack For free SMS
For this tricks, you need an Exp Sim of Reliance.
Now on SMS SETTINGS
1>Service centre No:- +919863002222
2>Validity period:- Maximum
3>Message type:- Text
4>Reply path:- Off
5>Delivery report:- Off
Note:- Your balance Must be Zero......