Choudhury, 58, who was denied an extension of service by the Union government till his superannuation age of 60 years, was sworn in by West Bengal Governor at Raj Bhawan today, a statement said.
His five year term as head of India's largest electricity producer came to an end in August and was eligible for an extension till he achieved superannuation age in 2017.
The West Bengal Right to Public Service Commission was constituted on September 18 under the West Bengal Right to Public Services Act, 2013.
The Commission shall start functioning from Kreta Suraksha Bhawan from today.