[14][15] In 2019, Viswanath co-founded Hindus for Human Rights (HfHR), a US-based advocacy organization that aims to promote religious pluralism in North America and South Asia.

[16] In 2021, Viswanath wrote a piece with Raju Rajagopal in favor of the Dismantling Global Hindutva conference in the face of criticism.

[17] In May 2021, Viswanath was a named defendant in a defamation case filed by the Hindu American Foundation, which was dismissed in 2022.

[25][26] In March 2022, Viswanath traveled to Afghanistan as part of a Women's Delegation for Peace and Education, which included Ruth Messinger, Medea Benjamin, Rev.

Chloe Breyer, Daisy Khan and Masuda Sultan, to advocate for women's rights and to deliver humanitarian aid.