law: Delhi Rent Control Act, 1958 
  16. Restrictions on sub-letting. -
  (1) Where at any time before the 9th day of
  
  June, 1952, a tenant has sub-let the whole or any part of the premises and the
  
  sub-tenant is, at the commencement of this Act, in occupation of such premises,
  
  then notwithstanding that the consent of the landlord was not obtained for such
  
  sub-letting, the premises shall be deemed to have been lawfully sub-let.
  (2) No premises which have been sub-let either
  
  in whole or in part on or after the 9th day of June, 1952,without obtaining the
  
  consent in writing of the landlord, shall be deemed to have been lawfully
  
  sub-let.
  (3) After the commencement of this Act, no
  
  tenant shall, without the previous consent in writing of the landlord,-
  (a) Sub-let the whole
  
  or any part of the premises held by him as a tenant; or
  (b) transfer or assign
  
  his rights in the tenancy or in any part thereof.
  (4) No landlord shall claim or receive the
  
  payment of any sum as premium or pugree or claim or
  
  receive any consideration whatsoever in cash or in kind for giving his consent
  
  to the sub-letting of the whole or any part of the premises held be the tenant.