Kathir has been working in the field of human rights for over 23 years. As a Dalit himself, he has been witnessing and experiencing caste-based discrimination since his childhood years. This triggered his determination to fight against the caste system and caste-based atrocities committed against Dalits. He started his career as a writer, addressing the experiences of the socially marginalized, but later shifted to a career in rights based interventions and human rights monitoring .His experiences and commitment to Dalit rights eventually led him to initiate Evidence in 2005, an independent organization fighting against caste discrimination and for social justice and equality for Dalit and Tribal people in the state of Tamil Nadu and the Union Territory of Puducherry( Pondicherry)