If you don't know how to do something, start with Google:
convert lat long to indian grid reference (GR) for India Zone 1A and Zone 0 - Google Search[
^] (You will no doubt notice that the search string was taken from your own question - so why didn't you try it?)
Loads of links, all explaining how to do exactly what you want...
Google is your friend: Be nice and visit him often. He can answer questions a lot more quickly than posting them here ...
In future, please try to do at least basic research yourself, and not waste your time or ours.