"I'm overjoyed with the response my latest album 'Back 2 Love' has received. And now to hear that the song 'Zaroori tha' has been featured in Mohit Suri's latest film 'Hamari Adhuri Kahani' is truly the icing on the cake," the 41-year-old singer said in a statement.
"The song will now get a new life as a Bollywood song and will reach out to a much wider audience," he added.
The song, which is picturised on Vidya and Emraan, captures the central theme of the film.
Suri, the film's director, said: "I firmly believe that a song finds a film and shapes its destiny. In my experience with music in most of my films, I have always found one of my key songs last. 'Zaroori tha' is one such song, and to me it feels like this song was always written for 'Hamari Adhuri Kahani'."
Veteran film producer Mukesh Bhatt, under whose banner Vishesh Films the movie is being released, says he has "very rarely found a song that expresses the story between two people so strongly".
"This heartbreaking song from Rahat has given great power to our love saga. Only a singer like him could capture the soul of this situation," Bhatt said.
The Universal Music artist, whose album "Back 2 Love" was released in June 2014, enjoys massive popularity in India with successful Bollywood numbers like "Tere mast mast do nain", "O re piya" and "Jag soona soona lage".