These aren't things that need to be arranged. People should always be online in the lug chatroom. Most of us from around India hang out in #linux-india on irc.freenode.net, and we have these online meet-ups about once a day for 24 hours at a time.
forming an auxillary IRC, Yahoo - etc list/room/group would be a good idea - as a) not everyone on this list is in mumbai and b) not everyone may be in town on the day of the meeting.