He was elected to the Tamil Nadu Legislative Assembly as an Indian National Congress (INC) candidate from Anna Nagar constituency in the 1991 election[1] and as a Tamil Maanila Congress (Moopanar) candidate from T. Nagar constituency in the 1996 election.
[4][5] Although he had joined the TMC(M) breakaway group in 1996 when factionalism beset the INC due to a decision to ally with the All Indian Anna Dravida Munnetra Kazhagam in the state, Chellakumar subsequently fell out with TMC(M) founder G. K. Moopanar.
His career then stalled for some years until, seen as a neutral figure with the INC, into which the TMC(M) had re-merged, he was one of three people appointed as a secretary to the Tamil Nadu All India Congress Committee in 2013.
[6] Chellakumar unsuccessfully contested the Krishnagiri Lok Sabha constituency for the INC in the 2014 elections for the Parliament of India, where he finished in a distant fourth place.
[7] A major reorganisation of the INC was thought to be necessary following its worst-ever defeat in those elections and as part of that process Chellakumar replaced Digvijaya Singh in April 2017 as the person in charge of the party's affairs in Goa.