John played the role of an undercover officer in the movie, set against the Sri Lankan civil war. The film, directed by Shoojit Sircar, released Aug 16.
The film was reportedly produced on a budget less than Rs.10 crore. But it earned over Rs.20 crore in its opening weekend.
"I am very happy and proud of 'Madras Cafe'. The film is growing by word-of-mouth. The film was made in a very smart budget and it is doing well at the box office," John said.
Apart from John, the film features Nargis Fakhri and newcomer Raashi Khanna. The casting, John says, is the film's USP.
"We have such a beautiful casting in the film, and it takes the film to another level," he said.