Activate 3G on your SIM

Simply follow the steps:

1.Insert your sim in 3G Phone
2.Do the following according to your service provider.
Vodafone:

Send a msg sms ACT 3G to 111 wait for
confermation msg and then let it be activated and then choose limits mode for 3G services

Airtel 3G:

Send a msg sms 3G to 121 wait for confermation msg and then let it be activated and then choose limits mode for 3G services

Idea:

Send a msg sms ACT3G to 12345 or 3G to 54777 wait for
confermation msg and then let it be activated and then choose limits mode for 3G services 1=mtnl 3G = 1 u have to send a msg to activate 3g on ur sim , insert that sim
in 3g fone then send a msg sms ACT3G to 444 wait for confermation msg and then let it be activated and then choose limits mode for 3G services

Tata Docomo 3G:

Send a msg sms ACT3G to 53333 or 3GLIFE to 53333 wait for confermation msg and then let it be activated and then choose limits mode for 3G services

Aircel 3G:

Send a msg sms START 3G to 121 wait for confermation msg and then  let it be activated and then choose limits mode for 3G services.