There were reports that the biopic would have a box office clash with Salman Khan's next on Eid 2018.
"All these are baseless rumours. The film will release as per schedule in March 2018," Hirani said in a statement.
Ranbir, who is currently busy promoting his production 'Jagga Jasoos', will be seen in six different looks in the film.
The biographical drama, written and directed by Hirani, is produced by Vidhu Vinod Chopra.
The movie is part of a three-film deal signed by Fox Star Studios with Hirani and Chopra.