Section 15(b) in Bombay Industrial Relations Act, 1946
(b)if [after giving notice to such union to show cause why its registration should not be cancelled and] after holding such inquiry, if any, as he deems fit, he is satisfied.(i)that it was registered under mistake, misrepresentation or fraud; or(ii)that the membership, of the union has for a continuous period of three [calendar months] fallen below the minimum required under section 13 of its registration:
