Try setting manual IP in Win10 to 192.168.1.2 and then try both gateway IP manual 192.168.1.1 and 192.168.1.254 ? Then see if you can at least login to the web UI of the Netlink device?
Also tried this. no juice.
Does the netlink device have a hard reset button/pinhole which you can press to factory reset the device? (but then you will lost the settings stored in the device) maybe best to get in touch with your LCO/vendor who provided you the connection. Maybe they have done some custom autoconfiguration from the OLT server side.
Yeah, I've called the BSNL guy as a last resort. He should help me reset the router and the configuration back in order. Thanks for all the help.