Section 147 in The Representation Of The People Act, 1951.
147. Casual vacancies in the Council of States. 1[
] When before the expiration of the term of office of a member elected to the Council of States, his seat becomes vacant or is declared vacant or his election to the Council of States is declared void, the Election Commission shall by a notification in the Gazette of India call upon the elected members of the Legislative Assembly or the members of the electoral college concerned 2[ , as the case
may be, to elect a person for the purpose of filling the vacancy so caused before such date as may be specified in the notification and the provisions of this Act and of the rules and orders made there- under shall apply, as far as may be, in relation to the election of a member to fill such vacancy.
1[ As soon as may be, after the date of commencement of the Constitution (Seventh Amendment) Act, 1956 , bye- elections shall be held to fill the vacancies existing on that date in the seats allotted to the States of Assam, Orissa and Uttar Pradesh and the Union terri- tories of Delhi, Himachal Pradesh and Manipur.]