In 1924 he passed from the High School. Shri. Sankar joined Maharajas College, Thiruvananthapuram, the present University College, with thehelp of a wealthy and benevolent relative, as his father could not afford the expenses for his education.

After graduating from Maharajas College, he joined Law College, Thiruvananthapuram in 1933.

After studies, Shri. Sankar took to teaching to earn a living. He joined Sivagiri High School as Principal. It was during those days, that he associated himself with the activities of the SNDP Yogam. A very good orator, he impressed many with his inspiring talks on the social injustice prevalent in those days, particularly the discriminatory attitude shown towards backward class communities. He also raised his voice for equal opportunities for backward classes, in all sectors. He studied Kumaran Asan’s poetry deeply and attended many literary meetings throughout Travancore.

Having started public life as a teacher and lawyer, he was drawn to politics with the birth of the State Congress. The end of the ‘Nivarthana agitation’ and the gradual growth of the State Congress, accelerated Sankar’s rise as a political leader. He participated in the freedom struggle and was arrested and put in jail. After India’s independence he focused his attention on strengthening the Congress party. Later, taking a break from the Congress party, he began to work in the SNDP Yogam.

His work during this period served a great deal to bring backward class communities into the fold of the Congress party. During his long association with the SNDP Yogam of over 13 years, he served the Yogam as its General Secretary, President and Chief of the SN Trust. Under his leadership the SNDP Yogam gave emphasis to the field of education and started many educational institutions.

Shri Sankar returned to the State Congress at a crucial juncture, when it was going through one of its worst periods. His organising skills and leadership qualities became evident in the election held after independence. He was elected to the Travancore Assembly in 1948. He also became a member of the Travancore-Cochin Assembly from 1949 to 1956. Shri. Sankar was a member of the Constituent Assembly and also a member of the Franchise and Delimitation Commission and the Reforms Committee constituted after the introduction of the Responsible Government. He led the Congress party as KPCC President during the 'Liberation Struggle'. The Congress won the elections in 1960 under Shri. Sankar’s leadership and he became the Deputy Chief Minister in the Pattom Thanu Pillai ministry. He handled Finance portfolio from 1960 to 1962. When Shri. Pattom Thanu Pillai was appointed as Governor, Shri. Sankar became the Chief Minister of Kerala from September 26, 1962 to September 10, 1964.

Shri. R. Sankar was an able administrator and statesman. His track record as the Chief Minister of Kerala is ample proof of his administrative skills. He brought about many economic reforms while handling the finance portfolio. He served as the Chairman of the Committee of Privileges from 1960 to 1964. He was also the editor of a newspaper called ‘Dinamony’.

His wife was Smt. Lekshmikutty Amma and they have one son and one daughter.
Shri. Sankar died at the age of 63 on November 6, 1972.
The Assembly paid its homage to him on November 13, 1972.