Hot, multi talented and a powerhouse performer Kangana Ranaut will be seen romancing with Ajay Devgan in Balaji's upcoming film 'Once Upon a Time in Mumbaai'.

Milan Luthria's directed 'Once Upon a Time in Mumbaai' was set mainly in 1970 Mumbai.

Kangana plays the role of Bollywood diva Rehana in the flick, which is a rewind to the era of romance, smuggling, cabaret and the mafia.

The film, which also stars Emraan Hashmi and Prachi Desai, will trace the changing face of the Mumbai criminal world through the eyes of a policeman.

The film is treated in an avante garde fashion, bursting with color, underlining the style of the 70s and 80s. A time when women had a liberated air to them, were fearless and bold.

On this, Milan Luthria said, "Kangana lends herself because she has a great body which does not look vulgar and her face is chameleon-like -- she can change into different looks everyday. There is a lot of her in her character Rehana" Kangana who worked hard on her look in the film studied the fads and trends rampant in the 70's not just in Bollywood but even in the West."

"Kangana's costumes were designed by Manoshi Nath and Rushi Sharma. She has done a lot of research on her role in the film and even went on to sketch out the preferred hairdo's accessories costumes and the works for her look in the film," a source said.

Kangana who worked really hard on her new avatar studied the trends rampant in the 70's not just in Bollywood but even in the West.

The film is due to release on 30th July 2010. (With Inputs from Agencies)