law: Delhi Rent Control Act, 1958 
  44. Landlords duty to keep the premises in
  
  good repair. -
  (1) Every landlord shall be bound to keep the
  
  premises in good and tenantable repairs.
  (2) If the landlord neglects or fails to make,
  
  within a reasonable time after notice in writing, any repairs which he is bound
  
  to make under sub-section (1) the tenant may make the same himself and deduct
  
  the expenses of such repairs from the rent or otherwise recover them from the
  
  landlord:
  Provided that the amount sod deducted or
  
  recoverable in any year shall not exceed one-twelfth of the rent payable by the
  
  tenant for that year.
  (3) Where any repairs without which the
  
  premises are not habitable or usable except with undue inconvenience are to be
  
  made and the landlord neglects or fails to make them after notice in writing,
  
  the tenant may apply to the Controller for permission to make such repairs
  
  himself and may submit to the Controller an estimate of the cost of such
  
  repairs, and, thereupon, the Controller may, after giving the landlord an
  
  opportunity of being heard and after considering such estimate of the cost and
  
  making such inquires as he may consider necessary, by an order in writing,
  
  permit the tenant to make such repairs at such cost as may be specified in the
  
  order and it shall thereafter be lawful for the tenant to make such repairs
  
  himself and to deduct the cost thereof, which shall in no case exceed the
  
  amount so specified, from the rent or otherwise recover it from the landlord:
  Provided that the amount so deducted or
  
  recoverable in any year shall not exceed one-half of the rent payable by the
  
  tenant for that year:
  Provided further that if any repairs not covered
  
  by the said amount are necessary in the opinion of the Controller, and the tenant
  
  agrees to bear the excess cost himself., the Controller may permit the tenant
  
  to make such repairs.