[2] Born into a Tamil family in Vellore, Viswanathan moved to Kolkata, West Bengal at an early age.
[4] While teaching at the college, he was offered a role in Punascha (1961), a Bengali film directed by Mrinal Sen.
Other Tamil films released during the period include Kavari Maan and Balu Mahendra's Moodu Pani, where he was cast in a prominent role.
[4] Viswanathan was also a member of Utpal Dutt's "People's Little Theatre" (PLT), and later formed his own group named "Calcutta Players".
[3] Mr. N. Viswanathan was an English news reader also in Calcutta Doordarshan TV channel and used to host Bournvita Quiz contest in radio.