law: Indian Divorce Act, 1869 
  16. Decrees for dissolution to be nisi 
  Every decree for dissolution of marriage made by a High Court
  
  not being a confirmation of a decree of a District Court, shall, in the first
  
  instance, be a decree nisi, not to be made absolute till after the expiration
  
  of such time, not less than six months from the pronouncing thereof, as the
  
  High Court, by general or special order from time to time, directs.
   Collusion-  During that period any person shall be at
  
  liberty, in such manner as the High Court by general or special order from time
  
  to time direct, to show cause why the said decree should not be made absolute
  
  by reason of the same having been obtained by collusion or by reason of material
  
  facts not being brought before the court.
  On cause being so shown, the court shall deal with the case by
  
  making the decree absolute, or by reversing the decree nisi, or by requiring
  
  further inquiry, or otherwise as justice may demand.
  The High Court may order the costs of counsel and witnesses and
  
  otherwise arising from such cause being shown, to be paid by the parties or
  
  such one or more of them as it thinks fit, including a wife if she have
  
  separate property.
  Whenever a decree nisi has been made, and the petitioner fails,
  
  within a reasonable time, to move to have such decree made absolute, the High
  
  Court may dismiss the suit.