The Special Marriage Act, 1954
37. Permanent alimony and maintenance. –
(1) Any court exercising jurisdiction under Chapter V or Chapter VI may, at the time of passing any decree or at any time subsequent to the decree, on application made to it for the purpose, order that the husband shall secure to the wife for her maintenance and support, if necessary, by a charge on the husband’s property, such gross sum or such monthly or periodical payment of money for a term not exceeding her life, as, having regard to her own property, if any, her husband’s property and ability and the conduct of the parties, it may seem to the court to be just.
(2) If the district court is satisfied that there is a change in the circumstances of either party at any time after it has made an order under sub-section (1), it may, at the instance of either party, vary, modify or rescind any such order in such manner as it may seem to the court to be just.
(3) If the district court is satisfied that the wife in whose favour an order has been made under this section has remarried or is not leading a chaste life, it shall rescind the order.