Punishment for illegal possession in small quantity for personal consumption of any narcotic drug or psychotropic substance or consumption of such drug or substance whoever, in contravention of any provision of this , or any rule or order made or permit issued thereunder, possesses in a small quantity any narcotic drug or psychotropic substance, which is proved to have been intended for his personal consumption and not for sale or distribution, or consumes any narcotic drug or psychotropic substance, shall, notwithstanding anything contained in this Chapter, be punishable (a) Where the narcotic drug or psychotropic substance possessed or consumed is cocaine, morphine, diacetylmorphine or any other narcotic drug or any psychotropic 343 substance as may be specified in this behalf by the Central Government, by notification i n the Official Gazette, with imprisonment for a term which may extend to one year or with fine or with both; and (b) Where the narcotic drug or psychotropic substance possessed or consumed is other than those specified in or under clause (a) with imprisonment for a term which may extend to six months or with fine or with both Explanation (1) For the purposes of this section "small quantity ' means such quantity as may be specified by the Central Government by the notification in the Official Gazette.