After Independence, the states were reorganized languagewise in 1956. Nesamani played a major role in the merger of Kanyakumari district with Tamil Nadu. He successfully led the popular agitation to liberate Tamil areas comprising the present Kanyakumari district in the Southern part of Tranvancore State and got it merged with Tamil Nadu. After the struggle, Kanyakumari District merged with Tamil Nadu on 1st November 1956.
Nesamani led agitations for the Socio-cultural Independence of the Tamilians and relating Kanyakumari as the Southern border of Tamil Nadu. He was called as the Marshal and Father of Kanyakumari district by the people of Kanyakumari.
In 1943, he was voted to the position of President of Nagercoil Lawyer’s Association. He was also elected as the Chairman of Nagercoil Municipal Council in the same year.
He started Travancore State Congress on 9th December 1945 for the cause of Socio-Justice struggle. He has been the member of Sri Mulam Assembly of Travancore from 1952 to 1968. He was also the member of Parliament of Nagercoil from 1962 to 1968.
Nesamani argued constantly for the merger of Southern taluks with the state of Madras in the parliament on the commission’s recommendations in the year 1955. As a result, Kanyakumari district was merged with Tamil Nadu in the year 1956.
First of November, The day on which Kanyakumari district was merged with Tamil Nadu is celebrated annually by garlanding and paying tribute to the Statue of Marshal Nesamani by the Government of Tamil Nadu.
Hon’ble Chief Minister of Tamil Nadu Selvi J Jayalalithaa inaugurated Manimandapam with the bust size Bronze statue of Marshal Nesamani constructed at a cost of Rs.48.70 lakh on 27.02.2014 in Nagercoil.