Can i use my ADSL wifi router with rj45 input (any converter for rj45 to rj11)?
Even with an adapter, this won’t work. You need a router with standard ethernet on the “Internet/WAN” input. An ADSL router has a modem inside to convert from the DSL line to ethernet fro the local network. Since you already have ethernet you simply have the wrong router. Since Reliance takes ethernet and supplies ethernet out, you might check, that “modem” they supplied may be a router! If it is, you can use you old router as a switch and still use it for wireless access.