1.contact your exchange and chek do you have 3G facility enabled on your tower if yes then buy a 3G SIM which cost Rs.59/- and selet a appropriate data plan you prefer and enjoy 3G you can also apply online here New 3G User Registration.
2.If you are a 2G SIM (prepaid) user,just send an SMS to 53733 as M3G120.Within mins you'll get a message to confirm.As soon as you reply with M3G120Y you will be migrated to 3G.(change may happen to this step.so use it with your own risk)
1. First migrate to a plan that is 3G compatible like plan 225 in case of postpaid.It can be done by submitting a request letter in your local bsnl telephone exchange.Once the plan migration is done you can send an sms to activate 3g services.
(change may happen to this step.so use it with your own risk)