Hi all,
I came to know that building an rc heli is a big task in itself and it is cheaper to buy a 3ch one. I was also told that I can also start by trying to make an aeroplane with foam first.
So, Could anyone give me a few tips to make one? Any help would be appreciated.  

There are lots of threads here on what is needed for build a plane, and what radio equipment is needed.  It will be really hard to get even a foam plane flying AND get the necessary radio equipment for under Rs2K, which you posted as the budget earlier.  The radio itself will cost more than that.  Please do consider this in your plans.

I don't know, I will try to buy a 3ch (or 4ch, if it's under my budget) heli.