Section 12(2) in The Standards of Weights and Measures (Packaged Commodities) Rules, 1977
(2)Except in the cases of commodities specified in the Fifth Schedule, the declaration of quantity shall be in terms of the unit of-(a)mass, if the commodity is solid, semi-solid, viscous or a mixture of solid and liquid;(b)length, if the commodity is sold by linear measure;(c)area, if the commodity is sold by area measure;(d)volume, if the commodity is liquid or is sold by cubic measure; or(e)number, if the commodity is sold by number:Provided that in the case of solid commodity contained in a free flowing liquid which is sold as such the declaration of quantity shall be in terms of the drained weight of such solid commodity.
