This was formally revealed by the director on the sidelines of the 69th Cannes Film Festival.
Nawazuddin, who is garnering rave reviews for his performance as a demented serial killer in the Cannes Directors' Fortnight entry "Raman Raghav 2.0", has already done costume tests for the role of the celebrated writer who left an indelible imprint on Urdu literature in a short-lived but brilliant career.
The funding of the film, being produced among others by Vivek Kajaria of Mumbai-based Holy Basil Productions, is in place and talks are on to put together the crew.
"But in India, economics always interferes with art and there was pressure on me to cast a more mainstream star," she adds.
Also Read
"But I absolutely need the kind of nuances and depth that only Nawazuddin can deliver."
Das says that her Manto is neither a big Bollywood film nor a small independent film. "We have to recreate Mumbai and Lahore of the 1950s and that demands a certain budget," she says.
The film will cover a period of seven years between 1946 and 1952, which was an important phase in the history of the subcontinent," says Das.
"Manto's simple yet profound narratives are today as relevant as ever," says Das.
"That is what draws me to him. He talks about everything I care for - freedom of expression, the question of identities thrust upon us, about wedges being driven between groups."