Next download ODIN from sammobile or samfw and install it on ur PC, then download the official indian firmware INS, latest version as of now dated JULY, BYG1 from sammobile. And manually flash it via odin... and make sure u choose HOMECSC in the CSC option, this is a crucial step as it will preserve all ur data safe without anything getting deleted and flash the firmware... hoorayy u got it... now from the next update u will receive OTA
I m **bleep** sure of this, yes i accept its a bit risky process where the risk starts from completely losing all of ur data to completely bricking device.. be cautious
