Section 18C(a) in Tamil Nadu Prohibition Act, 1937
(a)by duty of excise to be charged in the case or spirits or beer either on the quantity produced in, or passed out of a distillery, blending unit, brewery or warehouse licensed or established under this Act, or in accordance with such scale of equivalents, calculated on the quantity of materials used or by the degree of attenuation of the wash or wort, as the case may be, as may be prescribed ;