Section 5(3) in The Bombay Provincial Municipal Corporations Act, 1949
(3)Where general election is to be held immediately after,-(i)"a larger urban area" as specified under clause (2) of article 243Q of the Constitution of India, is made or(ii)the census is taken under the Census Act, 1948 and the relevant figures of which have been published, or(iii)the limits of a City are altered,-(a)the State Government shall, by notification in the Official Gazette, determine the number of wards into which the City shall be divided, the number of councillors to be elected to the Corporation and the number of seats to be reserved in favour of the Scheduled Castes, the Schedule Tribes, the Backward Classes and Women as provided in this section, and(b)the State Election Commission thereafter shall carry out the determination of the boundaries of the wards and the allocation of seats reserved in favour of the Schedule Castes, Scheduled Tribes, the Backward Classes and Women among the wards in the prescribed manner.
