law: 73. Any sale of articles on metro railway.
  If any person sells or exposes for sale, any article whatsoever in any metro railway carriage or upon any part of the metro premises not authorised by metro railway administration for such purpose, he shall be punishable with fine which may extend to five hundred rupees, and in default of payment of fine, he shall be punishable with imprisonment which may extend to six months:
  Provided that, in the absence of special and adequate reasons to the contrary to be mentioned in the judgment of the court, such fine shall not be less than one hundred rupees.