The song announcement was made by the film's director Atlee, via his official Twitter handle, along with a poster from the song.The background of the picture and the colour tone reminding us of Neethanae from the actor-director duo's previous film, Mersal.Unakaga has been sung by Sreekanth Hariharan and Madhura Dhara TalluriSreekanth Hariharan, incidentally, was one of the finalists in Super Singer Season 6.The song's lyrics have been written by Vivek, who has now become a regular in the star's films.The remaining songs from the film will be launched at the film's audio lauch at the Leo Muthu Indoor Stadium, Chennai.Interestingly, Vijay has issued a statement requesting his fan club members not to place hoardings and banners for the audio launch.Bigil is said to be a sports drama, with the Sarkar-actor playing dual roles of a son, who is a football player-turned-coach, and a gangster father.Nayanthara, who is playing the son Vijay's romantic interest, is said to have a significant role in the film.Bigil also features Indhuja, Varsha Bollamma, Amritha, and Reba Monica John as footballers, whose team will be coached by Vijay's character.Apart from them, Jackie Shroff, Kathir, Vivekh, and Yogi Babu are also part of the Bigil, playing supporting characters.Produced by AGS Entertainments, Bigil is slated for a Diwali release.