Thanks everyone for the awesome suggestions
Here's my experience till now (still 11 more hours to go) in the world's most busiest airport!
I landed in Terminal 4 and my transit is at Terminal 3. Went to board the bus and the lady over there told me that the bus connections are off during the night. EH! The busiest hotel actually sleeps at night...hard to believe :|
So I went to immigration and the officer was kind enough to grant me a 24hrs visa
Since it was already late at night (12am over here), I just did a peek-a-boo outside the airport and came in, bought a 24hours wifi pass and now sipping coffee and writing this, waiting for the shuttle to start operating and take me to the my terminal :P
So much for the busiest airport :P