law: 9. Purchasers or persons taking lease of apartments from apartment owners to execute an undertaking.-
  Notwithstanding anything contained in the Transfer of Property Act, 1882 (4 of 1882), or in any other law for the time being in the force, any person acquiring any apartment from any apartment owner by gift, exchange, purchase or otherwise, or taking lease of an apartment from an apartment owner for a period of thirty years or more, shall,-
  (a) in respect of the said apartment, be subject to the provisions of this Act; and
  (b) execute and register an instrument in such form, in such manner and within such period as may be prescribed giving an undertaking to comply with the covenants, conditions and restrictions, subject to which such apartment is owned by the apartment owner aforesaid.