First Step: Check the 3G compatibility in your phone.
A 3G enabled latest handset is all what’s needed to enjoy latest 3G services on airtel in. any part of country There are 2 types of 3G handsets available-HSPA & WCDMA, out of which HSPA is optional by experts. So just ensure that your mobile fits the bill for this 3G enables facility.
How to know that your handset is 3G enabled: Just SMS 3GHS to 121 from your airtel mobile number.
Second Step: To subscribe SMS 3G to 121 or call 12134.
These are as per latest update and going to change in future time