I asked a question on unix.stackexchange here
Nobody answered, but luckily I found solution on askubuntu here
I thought to answer my question myself by giving the link, so that other users can find solution to their similar problem.
but whenever I type the answer it gets converted to comment giving me this: answer +
Trivial answer converted in comment
this helped me, found it on askubuntu: https://askubuntu.com/questions/318973/how-do-i-create-a-wifi-hotspot-sharing-wireless-internet-connection-single-adap