Sundararajan was born in Nagapattinam 1880. He had his early education from St. Joseph's College, Trichinopoly and graduated in medicine from Royapuram Medical School, Madras. Following his graduation, Rajan moved to Burma and set up practice in Rangoon. In 1907, Rajan sailed to England to pursue his higher studies. He obtained his M.R.C.S. degree in 1911 and worked in the Middlesex Hospital. He was an acclaimed surgeon and physician. Rajan returned to Burma soon after and practised till 1914, before returning to India. In 1923, he set up his own clinic called "Rajan Clinic".
During his days in England, Rajan was a close associate of V. D. Savarkar and V. V. S. Aiyar and was a member of the India House. However, in May 1910, Rajan had a quarrel with Aiyar. On his return to India in 1914, he met Rajagopalachari and joined the Indian National Congress. He participated in the agitations against the Rowlatt Act and was jailed for a year. He also coordinated and organised the activities of the Khilafat Committee from 1920 to 1922 along with T. V. Swaminatha Sastri. Rajan served in a number of party posts in the Indian National Congress over the years. He served as the General Secretary of the Congress and as the President, and later, Secretary of the Tamil Nadu Congress Committee. He also served as the President of the Civil, Social and Welfare League of Trichinopoly. Rajan participated in the Vedaranyam Salt Satyagraha organised by Rajaji and suffered imprisonment. He was released in 1931 after having been in prison for eighteen months. From 1932 to 1935, Rajan served as the President of the Tamil Nadu branch of the Harijan Sevak Sangh. In 1934, Rajan was elected to the Imperial Legislative Council of India and served till 1936, when he resigned owing to differences of opinion. Rajan participated in the 1937 Madras provincial elections and was elected to the Madras Legislative Council. He took the portfolios of public health and religious endowments in the Rajaji cabinet.
Later years and death
In 1946, when the Congress was elected to power once again in Madras Presidency and Tanguturi Prakasam became Premier, Rajan was appointed Minister of Food and Public Health. He served as minister till 1951. In 1953, Rajan had an operation for appendicitis. Shortly after the operation, he died on 14 December 1953 at the age of 73.
