Section 5A(4)(b) in The Mumbai Municipal Corporation Act, 1888
(b)[one-half] [These words were substituted for the words 'one-third' by Maharashtra 20 of 2011, Section 2(2), (w.e.f. 21-4-2011).] of the total number of seats reserved under clause (a) shall be reserved for women belonging to the Backward Class of citizens.