Fawad Khan was originally cast to play the role of main protagonist, but Sidharth Malhotra replaced him after ongoing India/Pakistan conflict over the Kashmir region led for a call to ban all Pakistani actors from Indian films.
B.R. Chopra produced the original film, Ittefaq (1969). B.R. Chopra's grandson Abhay Chopra makes his directorial feature film debut with this film.
While in making the makers had disclosed that the film would have a different climax from original to keep the suspense alive.
Movie doesn't have any songs. Quite rare in Bollywood.
Shah Rukh Khan was to play the character of the detective (Akshay Khanna's role), but opted out to work on Fan (2016) and Raees (2017).