If 3G service is activated on your sim then you cannot activate 2g gprs packs on your sim. ( recharges won’t be successful , i have tried it)IF you want to use 2G gprs pack you need to revert back to 2G service. Dial *123# and know in which plan you are in , it show something like this Plan:xxxx.Send SMS from your mobile ( M2G to 53733) to revert back to 2G and then you can recharge any 2G gprs pack. Ex: 98 rs ,3gb usage, val 30daysNext time post your query in "mobile services and phones" / "3g in india" section