According to the Rajya Sabha website, the Constituent Assembly, which first met on December 9, 1946, also acted as the Central Legislature till 1950, when it was converted as ‘Provisional Parliament’. During this period, the Central Legislature, which was known as Constituent Assembly (Legislative) and later Provisional Parliament, was unicameral till the first elections were held in 1952. Extensive debate took place in the Constituent Assembly regarding the utility or otherwise of a second chamber in independent India and ultimately, it was decided to have a bicameral legislature for independent India mainly because a federal system was considered to be most feasible form of government for such a vast country with immense diversities. A second chamber known as the ‘Council of States’, therefore, was created with altogether different composition and method of election from that of the directly elected House of the People. It was conceived as another chamber with smaller membership than the Lok Sabha (House of the People). It was meant to be the federal chamber, a House elected by the elected members of Assemblies of the states and two Union Territories in which states were not given equal representation. Apart from the elected members, provision was also made for the nomination of 12 members to the House by the President. The nomenclature “Rajya Sabha” was announced by the Chair in the House on August 23, 1954.
Source: Economic Times