Starring Rajkumar Rao, the movie revolves around a government clerk who tries to conduct fair voting on an election day amid the fear of guerrilla attacks and apathy of security forces.
The drama-comedy has been directed by Amit V Masurkar and was India's official entry to Oscars 2018.
Meanwhile, actor Pankaj Tripathi also got the 'Special Mention Award' for his role in 'Newton'.
The announcement came from the chairperson of the Feature film category.
A 10-member panel sat on Friday to announce the winners of the 65th National Film Awards.
Jury members include Kannada director P Sheshadri, screenwriter Imtiaz Hussain, Aniruddha Roy Chowdhury, Tripurari Sharma, South Indian actress Gautami Tadimalla, Ranjit Das, Rumi Jaffrey, lyricist Mehboob, and Rajesh Mapuskar, headed by director Shekhar Kapur.
After the announcements, the official ceremony will be held on May 3. The awards will be given by President Ram Nath Kovind. (ANI)