law: The Delhi Municipal Corporation Act, 1957
  166. Notice to be given of the circumstances in which remission or refund is claimed.-
  No remission or refund under section 164 or section 165 shall be made unless notice in writing of the fact that the land, building or tenement has become vacant and unproductive of rent has been given to the Commissioner, and no remission or refund shall take effect in respect of any period commencing more than fifteen days before delivery of such notice.