Divorce is nothing to do with Child custody;
You have to file seperate appeal for Custody under guardian act ( In India)
Check this out http://mynation.net/custodyfaq.htm
Unless you have custody you cann
t take him out of country, If you are taking him to Middle east then you cannt sponsor child (Unless you hold noble job)
and in west its treated as abduction, and visa officer will ask custody papers or father permission as your status is DIVORCEE.
If you are coming to india, then Indian immigration will not ask about child papers as you are Indian origin but they may ask Child Papers, if current country allow you to board the plane.