How to become a commercial pilot?

You have to attend an commercial pilot course in any aviation Academy, then waiting for even for any chance : ) 

After your course ,you have to check big airlines and check what is the minumum flying hours they require as per their policies .
It will cost you a bit to reach the limit of certain airlines but you can start with chartered airlines and then as you have in your account200-300 hours you look for big airlines like Qatar,Etihad or Emirates