Chathunni is survived by his wife and two daughters.

A well-known defender of the 1960s and 1970s, Chathunni was a member of the Indian team in the 1973 Merdeka tournament in Kuala Lumpur. He played six matches for the national team.

In domestic football, he played for EME Centre, Secunderabad, Vasco Club, Goa and Orke Mills, Mumbai. In the National Football Championship for the Santosh Trophy, he played for Services.

AIFF President Kalyan Choubey said, "Chathunni was a dependable defender and later a top-class coach. I express my deepest condolences to his family in this hour of grief."

In the following years, Chathunni turned to coaching and worked with several teams including the Kerala Santosh Trophy team, Kerala Police, FC Cochin, Mohun Bagan, Salgaocar FC, Dempo Sports Club and Churchill Brothers.

AIFF acting general secretary M Satyanarayana said, "TK Chathunni was an iconic footballer of his time and continued to inspire subsequent generations of footballers with his coaching. His death has left a void in Indian football."