The firmware must be from the TP-Link India Support Site . Using European or US firmware on an Indian (IN) branded router can lead to issues with wireless channel compliance. 3. TP-Link TL-WR850N V3 Firmware Download (India Fixed)
Go to System Tools -> Firmware Upgrade . tplink tlwr850n v3 firmware download india fixed 2021
Navigate to Advanced > System Tools > Firmware Upgrade . The firmware must be from the TP-Link India Support Site