It's not working on my friend's S5 either and it was working on iPad Air 2 cause it supports all the LTE bands (1, 2, 3, 4, 5, 7, 8, 13, 17, 18, 19, 20, 25, 26, 28, 29, 38, 39, 40, 41) Airtel either owns only the 2300 Mhz band (40) in Mumbai or might be in the process of expanding to other bands...