These days, its seems like Airtel is just rolling the floor with super loot offers. After 1GB data at Re 1, it is now offering free 1GB 4G data just on dialing a number. The offer is only for those users who had upgraded their Sim to 4G in Delhi/Mumbai. So, dial now and check your data luck !!
Note:- The offer ihas been verified in Delhi/Mumbai/Kerala and for those users who had upgraded their Sim to 4G. Still, you can give a try #FingerCrossed !!