Actor Siddhanth Kapoor, who will be essaying the role of fugitive don Dawood Ibrahim in the biopic on the gangster's late sister Haseena Parkar, says the film is challenging both for him and his sister Shraddha.

The film "Haseena - The Queen of Mumbai" will have Shraddha Kapoor playing the title role.

The movie, to be directed by Apoorva Lakhia, will chronicle Haseena's life from the age of 17 to 40.

"I am really happy to be working with Shraddha. It is going to be the most challenging film for both me and Shraddha and I am sure both of us will pull it off," Siddhanth told PTI.

"The film spans from 1970s to early 2000 (and) there will be a transformation in our looks. Besides this, we have to get the diction, accent right. We both will soon start with the workshop," he said.

For his role as Dawood, Siddhanth will have to gain 10 kilos of weight and he is also tying various looks.

"It's an interesting story to be told. It's a hard hitting fast paced film so it is difficult in a way. I have been to Dongri (an area in South Mumbai), when I was shooting for 'Shootout at Wadala'. It will be a new space for Shraddha," the 31-year-old actor added.

Initially, it was Sonakshi Sinha who had agreed for the role but she later opted out.

"I was part of the film much before Shraddha came on board. Sonakshi (Sinha) couldn't be part of the film due to date issues and (director) Apoorva (Lakhia) felt (that) Shraddha was the right choice," Siddhant added.

The film will go on floors in November this year.