Yes. It is indeed 'Coolie No 1', which was probably Tabu's first film which got released. Here is the youtube link. (Especially for Tabu fans :) )
http://www.youtube.com/watch?v=_i0nyA4lHgQ
And here is another wonderful Telugu song, a duet sung by Raja for that horrible film, 'Mallepoovu' (Which incidentally Plum watched :) )
http://www.youtube.com/watch?v=b_IRbt1caYA
Raja also has a couple of other Telugu duets in the film 'Yedukondala Swamy'. They are also lovely songs.