Rajamony worked in the Indian Mission to the UN in Geneva as officer responsible for human rights and humanitarian matters. In 1996, he was elected Rapporteur of the UN Commission on Human Rights representing India.

He has also served in the Indian Embassy in Washington DC as the official spokesperson and in the External Publicity Division of the Ministry of External Affairs headed by the Official Spokesperson of the Ministry.

Rajamony is fluent in Chinese (remember, he served nine years in China (Beijing) and Hong Kong). During this stint, he authored a monograph titled "The India-China-US Triangle: A Soft Balance of Power in the Making" which has been translated into Chinese and cited in various books and publications.