^^ Well, I tried that. ( I just wanted to hear the answer from the OP)
I converted an English subtitle file (.srt) through Google translator and copied the converted data to another .srt file. And tried running the video with the new subtitle file. Result, all text comes as, ????????? ?? ?????.
So here is the little research I made to find out the reason: (it may be technical).
Normal .srt file is in ANSI format. But when I tried to save the converted file as .srt file in notepad, it said, I would have to save it as Unicode file, since the ANSI standard doesn't support hindi characters.
Now IMO, VLC is not able to read Unicode characters, so it displays the characters as "?" marks. I tried changing various settings pertaining to Subtitles in VLC, but all in vain.
So, I think, we need a player, that supports Unicode subtitle reading. And the problem would be solved.