Listen to Oi Harinaam Mahamantra online. Oi Harinaam Mahamantra is a Bengali language song and is sung by Subhasish. Oi Harinaam Mahamantra, from the album Mayer Mato Aponjon Ke Achhe Jagate Mon, was released in the year 2019. The duration of the song is 5:39. Download Bengali songs online from JioSaavn.