Educated in law and trained as a jurist from the United Kingdom, he earned notability and international fame when he chaired the War Enquiry Commission to investigate the of the war with India that led the liberation of East Pakistan and provide insightful recommendations to prevent future armed foreign intervention. In addition, Rehman served as a law professor in the faculty of Karachi University and vice-chancellor of University of Dhaka while remaining active in promoting literacy across the country. After the independence of Bangladesh, Rehman's family retained Pakistan's citizenship and his son served as the Chief Justice of Islamabad High Court.