Section 527(3) in Kolkata Municipal Corporation Act, 1980
(3)If no such undertaking as is referred to in sub-section (2) is given, or if in a case where any such undertaking has been given, any work of improvement to which the undertaking relates is not carried out within the specified period or the building is used in contravention of the terms of the undertaking, the Municipal Commissioner shall forthwith make an order of demolition of the building requiring that the building shall be vacated within a period to be specified in the order not being less than thirty days from the date of the order and demolished within six weeks after the expiration of that period.