<P> In June 1947 delegations from Sindh, East Bengal, Baluchistan, West Punjab and the North West Frontier Province withdrew to form the Constituent Assembly of Pakistan, meeting in Karachi . On 15 August 1947 the Dominion of India and Dominion of Pakistan became independent nations, and members of the Constituent Assembly who had not withdrawn to Karachi became India's Parliament . Twenty - eight members of the Muslim League joined the Indian Assembly, and 93 members were later nominated from the princely states; the Congress Party secured a majority of 82 percent . </P> <P> At 11 am on 9 December 1946 the Assembly began its first session, with 208 members attending . By early 1947, representatives of the Muslim League and princely states joined, and the Assembly approved the draft constitution on 26 November 1949 . On 26 January 1950 the constitution took effect (commemorated as Republic Day), and the Constituent Assembly became the Provisional Parliament of India (continuing until after the first elections under the new constitution in 1952). </P> <P> Dr. Sachchidananda Sinha was the first chairman (temporary) of Constituent Assembly . Later Dr. Rajendra Prasad was elected as the president and Its vice-president was Harendra Coomar Mookerjee, a Christian from Bengal and former vice-chancellor of Calcutta University . Also chairing the assembly's Minorities Committee, Mookerjee was appointed governor of West Bengal after India became a republic . Jurist B.N. Rau was appointed constitutional adviser to the assembly; Rau prepared the original draft of the constitution, and was later appointed a judge in the Permanent Court of International Justice in The Hague . </P> <P> The assembly's work had five stages: </P>

Who was the chairman of the union powers committee of the constituent assembly