The film's music composer M.M Keeravani also worked free of cost.
"Charmi loved her character so much that she decided to do it free of cost. Keeravani wanted to offer his music as a tribute to Nirbhaya. I think this is their way of playing tribute to her," the film's director Thammareddy Bharadwaja told IANS.
Charmi plays the role of a journalist in the film.
"I think this is the most powerful role of her career. She fights for the victim and has some very strong lines to mouth. I'm sure the audience will be moved by her performance," he added.
Director Bharadwaja, who is wielding the megaphone after six years, said he won't take any long breaks hereafter.
"I have been busy with so many other commitments in the last few years. I won't take any breaks and keep myself occupied with films," he said.
His last directorial was Telugu romantic-drama "Pothe Poni".
--IANS (Posted on 02-01-2014)