Viswanathan has participated in many international and national art festivals, including Biennale de Paris and the International Biennale of Engraving at Ljubljana and several art galleries such as Galerie, Ved Aaven, Aarhus, Galerie de France, Galerie Stig Carlsson, Höganäs, Centre Georges Pompidou, Vadehra Art Gallery, New Delhi and National Gallery of Modern Art have staged his one man shows and retrospectives. He was also involved with the "Art Rises for Kerala" (ARK) initiative at the 2019 edition of the Kochi-Muziris Biennale where his paintings were auctioned to raise funds for the reconstruction activities of the Government of Kerala in the wake of the 2018 Kerala floods. He has also made a few films, starting with a series titled, "The Pancha Bhoota" consisting of 5 films, "Ganga" as well as a series titled "Back to Elements".