Section 7(3)(a) in Sikkim Land (Requisition and Acquisition) Act, 1977
(a)such award shall be filed in the office of the Collector and shall, except as hereinafter provided, be final and conclusive evidence, as between the Collector and the persons interested in the land, whether they have respectively appeared before the collector or not, of the true area and value of the land and the apportionment of the amount among the persons interested;