rj45 to rj11

I am currently using a MTNL connection which came along with adsl2 router The of router is Binatone model no. dm 856w In one of the forum post itself : *www.thinkdigit.com/forum/networking/174925-any-router-can-work-rj11-well-rj45-input.html It mentions that even a adsl2 router...