Section 3(1)(b) in The Black Money (Undisclosed Foreign Income and Assets) and Imposition of Tax Rules, 2015
(b)valuation of archaeological collections, drawings, paintings, sculptures or any work of art (hereinafter referred to as artistic work) shall be the higher of,-(I)its cost of acquisition; and(II)the price that the artistic work shall ordinarily fetch if sold in the open market on the valuation date for which the assessee may obtain a report from a valuer recognized by the Government of a country or specified territory outside India or any of its agencies for the purpose of valuation of artistic work under any regulation or law;