Notwithstanding anything contained in this Act, -

(a) a tax on the sale or purchase of goods shall not be imposed under this Act -

(i) where such sale or purchase takes place outside the State of Himachal Pradesh; or

(ii) where such sale or purchase takes place in course of import of the goods into, or export of the goods out of, the territory of India; and

(b) a tax on the sale or purchase of any goods shall not be imposed where such sale or purchase takes place in the course of inter-State trade or commerce except in so far as Parliament may by law otherwise provide.