Section 12(3) in The Indian Stamp (Goa, Daman and Diu Amendment) Act, 1968
(3)The Collector may on his own motion or otherwise, within two years from the date of registration of any instrument of conveyance, exchange or gift not already referred to him under sub-section (1), call for and examine the instrument for the purpose of satisfying himself as to the correctness of the market value of the property as set forth in such instrument, which is the subject matter of conveyance, exchange or gift and the duty payable thereon and if after such examination he has reason to believe that the market value of such property has not been truly set forth in the instrument, he may determine the market value of such property and the duty as aforesaid in accordance with the procedure provided for in sub-section (2) and, thereupon, the difference, if any, in the amount of duty, shall be payable by the person liable to pay the duty:Provided that nothing in this sub-section shall apply to any instrument registered before the date of the commencement of the Indian Stamp (Goa, Daman and Diu Amendment) Act, 1975.
