Do not use TL-WR850N v3 with any “2021 fixed” firmware. Upgrade to a newer model like TP-Link Archer C6 or C20, which receive official India-specific firmware updates for BSNL/Airtel/Jio.
received a significant "fixed" update in 2021 to address stability and performance issues reported by users in India. 3.16.0 0.9.1 v6031.0 Build: 210407 Rel.7370n Release Date: April 7, 2021 tplink tlwr850n v3 firmware download india fixed 2021
Connect your PC to the LAN port, open a browser, and enter tplinklogin.net or 192.168.0.1 . Do not use TL-WR850N v3 with any “2021 fixed” firmware