just dial a number from upgraded your sim 4g. This offer is only user who had
upgraded Airtel sim to 4g sim selected states only so check your luck for free
How to 1gb 4g data Airtel .
1 First dial number 52122 to upgraded your sim.
2 Now airtel send Confirmation message.
3 Your 1gb free data add your number.
Note:YOU USE 1GB DATA 4G MODE ONLY, *121*2# CHECK YOUR 4G DATA
MORE INFO THIS OFFER.
1 Free data only working 4g mode.
2 Valid only some states.
3 Free data only for change your sim 4g.