The Student of the Year director is one of three of India's leading filmmakers to produce a short for the documentary commemorating 100 years of Indian cinema.
Johar told IANS: "[Bombay Talkies] has four directors - Zoya Akhtar, Anurag Kashyap, Dibaker Banerjee and myself. We all are making the 20-minute short film.
"The film will be releasing on May 3 because that is the anniversary date and ironically, that's a Friday. It is a different film and definitely what holds all these four films together is the passion for Indian cinema."
Johar's segment features Rani Mukherji and Randeep Hooda. Zindagi Na Milegi Dobara director Zoya Akhtar has reportedly completed her section of the documentary, which features Katrina Kaif.
Anurag Kashyap is rumoured to be filming his section with Amitabh Bachchan, while Dibakar Banerjee is said to have cast Nawazuddin Siddiqui.
Bombay Talkies marks 100 years since the release of India's first motion picture Raja Harishchandra in 1913.