Deshmukh plays Purab Shastri, an investigative television reporter in the film, which is Varma's take on journalism in India and stars megastar Amitabh Bachchan as a media baron.
"The reason I went for a change in 'Rann' is because whenever people look at me, they think I am going to make them laugh. Because I have been attached to comic films, most of them feel that I will come on screen and make some funny faces," Deshmukh said about his image as a comic actor.
"I am doing something serious and I want them to take me seriously. I asked Ramu that I wanted to go for a change. I just went for a complete makeover," the actor said.
Deshmukh, 31, is sporting a close-cropped hair and a stubble in the movie, which hits the theatres on January 29.
"The reason behind this is that my character is very serious. He hardly laughs. In the entire film I have probably smiled once or twice. I don't want people to say, 'now he is trying to be serious'. I want to look the part," he said.
Talking about his role in the movie, Deshmukh said he plays a very intense character.
"My role is of an extremely righteous guy. He is someone who thinks that life is in black and white and if he thinks he is right he will go to any extent to prove his point. He is an investigative journalist and he believes that the profession is an important and responsible job," he said.Talking about the recent reports of his wedding to his 'Masti' co-star Genelia D'souza, Deshmukh said he was 'shocked' by it.
"I was shocked by these reports. I am just waiting for them to give the date. I have learnt to live with it. Is there any other option?," he said.
The actor may not like to be the target of such news reports but enjoyed his turn as a scribe in the film, which helped him understand the workings of the media organisations.
"The sting operation that I did in 'Rann' was good fun. I had never done something like that in my entire life. They are a reality today thanks to the media but when you are at the receiving end, it does not sound good," he said.
Deshmukh will next be seen 'Housefull' and 'Jaane Kahan Se Aayi Hai', which will see him playing a romantic role after a long time.
The actor started his Bollywood journey with 'Tujhe Meri Kasam' in 2003 and tasted success with multi-starrer comedy 'Masti' in 2004. Since then he has starred in a string of comedy films including hits like 'Kyaa Kool Hai Hum', 'Malamaal Weekly' and 'Apna Sapna Money Money' and 'Heyy Babyy