Section 81(2)(b) in The Calcutta Improvement Act, 1911
(b)shall offer to the said person, or his heirs, executors or administrators, a prior right to take on lease or to purchase such land, at a rate to be fixed by the Board, if the Board consider that such a right can be given without [prejudice to public interest or] [Inserted by W.B. Act 32 of 1955.] detriment to the carrying out of the purposes of this Act.