Set on a college campus, the film - said to be just over two hours long - is a departure for the director who is famous for making films which are epic in scale and duration, DNA India reports.
"This is going to be the shortest film of my career. Though I am yet to arrive at the final cut, it should be around 135-140 minutes at maximum," said Johar.
A source close to Johar said that the cast of newcomers was a key factor in the director's decision to keep the film short.
"Student of the Year hasn't been designed as a saga per se that requires an extended story to be told," they said. "Moreover, this is the first time Karan is working with newcomers.
"With superstars you can still hold the audience for three hours but with newcomers it's better to keep it short and simple."
At 215 minutes, Johar's tale of marital discord Kabhi Alvida Naa Kehna is his longest film. The multi-starrer Kabhi Khushi Kabhie Gham is 211 minutes long, while Kuch Kuch Hota Hai has a duration of 185 minutes. At 165 minutes, My Name Is Khan is Johar's shortest film to date.
Featuring an updated version of the 1981 cult disco classic 'Disco Deewane', the film is reportedly based on US TV series Glee.
Student of the Year stars newcomers Alia Bhatt, Varun Dhawan and Siddharth Malhotra.
The film is scheduled for release on October 19.
Watch the song 'Disco Deewane' below: