Listen to Unakkum Rahasiyam online. Unakkum Rahasiyam is a Tamil language song and is sung by P. Susheela, T.M. Soundararajan and M.S. Viswanathan. Unakkum Rahasiyam, from the album Samayal Karan, was released in the year 1974. The duration of the song is 3:13. Download Tamil songs online from JioSaavn.