Born on November 8, 1955, Justice Ranjit Kumar Bag passed MA in Linguistic securing First Class and obtained LLB Degree from Calcutta University. He joined West Bengal Judicial Service in the year 1983. He got promotion to the cadre of District Judge in 2001 and presided over Special Court under N.D.P.S Act, Alipore in 2002. He held the posts of (i) District and Session Judge, Malda, (ii) Chief Judge, City Session Court, Calcutta, (iii) Registrar General, High Court at Calcutta and (iv) Director of West Bengal Judicial Academy.
He taught Criminal and Constitutional Law to the IPS Officers undergoing induction and in-service training in Sardar Vallabbhai Patel National Police Academy, Hyderabad while he worked there on deputation from 1995 to 1999. He is the author of three books – (i) Law of Medical Negligence and Compensation, (ii) Supreme Court on Criminal Justice and (iii) Service Laws of Government employees. He attended 12th International Congress on Criminology at Seoul, South Korea as delegate of Government of India in 1998.
He worked as Judge of High Court at Calcutta from October 1, 2013 to November 7, 2017. He joined West Bengal Administrative Tribunal as Member (Judicial) in the afternoon on January 25, 2018.