If you entered your pin wrongly three times, then the sim will be locked and to unlock you must need PUK. without PUK you cannot be able to unlock the sim card. Now you may be thinking how to get the puk of locked sim.
How to find PUK code for Airtel sim card
It is very easy to get the PUK, all you have to do is just call Airtel Customer care through your another Airtel number or from your friend mobile who are using Airtel.
Type your mobile no. and send it to 785.
PUK space your mobile no. and send it to 121.
Before calling customer care make sure you have
1.The 8 -15 unique number printed on your sim card, Incase if you dont have it on your simcard you may find it in the cover pack which comes with new sim card.
2.The name of the owner of the sim, owner means the name which you have given when you are buying the new sim.
3.There are some rare cases where they ask about the last recharge amount or date.