"Inkaar" deals with sexual harassment at work-place and also stars Chitrangada Singh.
Rampal, 40, has successfully managed to shake off his wooden face image with films like "Raajneeti", "Rock On" and Mishra says that he is growing as an actor.
"Arjun is growing as an actor. Finally films are also changing and it suits him more as an actor. Though he has got all the looks, he is not stylised sort of typical Hindi film hero actor. He is actually a very good actor and is comfortable with our kind of films more," Mishra, who has made films like "Hazaaron Khwaishein Aisi", "Dharavi" and "Chameli", told PTI.
The filmmaker also said that Rampal is lucky to be part of the industry at a time when it is changing.
"When you see 'Rock On', 'Raajneeti', he is very good. He is lucky that Indian cinema has changed in his time and the kind of films that are being made gelled with his kind of acting," Mishra said.
"Inkaar" will hit theatres this Friday.
Mishra is currently working on "Mehrunnisa", which may star actor Amitabh Bachchan in the lead but the director said that he is still in the casting process.
"I am thinking of lot of films. "Mehrunnisa" will have big stars. I do not have any problem with big stars, they are good for a film as they bring a huge fan base of their own and many of them are very good actors like Aamir, Saif and Amitabh Bachchan. I would love to work with any of them. I have finished the script."
"There is another film that will come after 'Mehrunnisa'. It is produced by Farhan Akhtar's Excel Entertainment and co-produced by Balaji. It is a very interesting love story set in a political background," Mishra said.