Ajay Devgn and Sanjay Dutt reprise their characters Sultan Mirza (from Once Upon A Time In Mumbaai) and Raghu (from Vaastav) respectively in David Dhawan's Rascals.

Also...

Sanjay is named Chetan while Ajay is called Bhagat in the comic caper. Wonder what writer Chetan Bhagat has to say!