I have a Tenda 300Mbps N301 wireless router that connects to the ISP with its WAN through a cable that has an RJ45(Ethernet) plug. I would like to use my this router on its WAN, with RJ11(Telephone line-India) plug.
Can I use an RJ11 to RJ45 converter to plug the cable from the ISP to Router without any physical modem? Is there any DIY way to make it work without physical modem seperately?If my router is inadequate can I still do this with the proper router?
No. It's not just the plug that is different, but the signalling itself. The router expects to talk Ethernet via its 'RJ45' ports, but the phone line usually provides ADSL, which uses different electrical signals and carries different data formats as well.
(Not to mention that the usual kind of Ethernet requires at least two twisted pairs – four for GbE – and most phone lines I've seen only have one pair of wires...)
So, you must somehow convert the ADSL signal to an Ethernet signal, and as @sawdust already mentioned in the comments, that's called a "DSL modem".
A router cannot perform the functionality of a modem.
Find out whether your ISP provides an DSL, ADSL or VDSL connection and buy a router plus modem combination device.
No one is smart enough to make a cable and connect pins 1,2,3,4 of an RJ11 plug on one end to pins 1,2,3,6 of an RJ45 male connector on the other end. Plug this cord into a router on one end and an RJ11 wall plug at the other end. Cross connect it to another RJ11 wall plug in your house and use another cable of the same wire connection. This gives you 100M ethernet over phone wiring (up to 100'). Wire has to be strait through and not part lined with other phone wiring in the house. I have yet to find a premade cable with this connection scheme. If anyone else finds such a cable, I am an eager buyer.
