15. Power of State Government to grant refund of tax

  (1) The Government may, if it is necessary so to do in the public interest and subject to such conditions as it may impose, by a notification, provide for grant of refund of tax paid to any person, on the purchases effected by him and specified in the said notification.

  (2) Any notification under sub section (1) may be issued so as to be retrospective to any day not earlier than the appointed day and such notification shall take effect from the date of its publication in the Gazette or such other earlier or later date as may be mentioned therein.

  (3) An application for refunds shall be made in duplicate to the Commissioner within a period of six months from the date of purchase or as the Government may prescribe in the notification and it shall be accompanied by the purchase invoice in original.