John is also the co-producer of the film, which is coming out Friday.
Nargis, who made her debut as Ranbir Kapoor's love interest in "Rockstar" in 2011, said working with John was really nice.
"He was very funny and easy going. The best part was anytime I did well, he would comment how well I did.
And I think that's really sweet and also really important for someone like me, who is only a film old and who needs a little bit of self-esteem lift... especially when it comes from someone who is talented, senior, and who has done so many different types of films... it felt really nice," added Nargis.
Directed by Shoojit Sircar, "Madras Cafe" is a political thriller that revolves around the Sri Lankan civil war.