Ali Abbas Zafar says though major parts of Gunday will be shot in Kolkata, he will create Howrah streets in Mumbai only.
"My film Gunday will go on the floors from Dec 7. Since it's a period film, we are working too much on the pre-production. Major portions will be shot in Kolkata but we are creating the streets of Howrah in Mumbai and it will take some time," Zafar said.
"The set will not be created in any studios, it will be shot outdoors to make it look authentic," he added.
If his directorial debut Mere Brother Ki Dulhan was a light-romantic comedy, Gunday will depict mature romance.
"This is a different kind of a film. It's a more mature romance and it also has action and drama. I am planning to release the film in the winters of 2013," he said.
Praising the cast of the film, he said "wonderful actress" Priyanka Chopra is playing the female lead.
"She will look authentic and justify her character as a Bengali girl. All the three characters will be seen as Bengali in the film," he said.
Ranveer Singh and Arjun Kapoor have been finalised as the male leads in it.
"There will be some surprise as well. There will be some special appearances in the film by regional actors," he added.
Set in the 1970s, it deals with black marketing mafia men Bikram (Ranveer) and Bala (Arjun) in Calcutta (now Kolkata).