Section 17(2)(b) in West Bengal Value Added Tax Act, 2003
(b)purchases of goods which are shown to the satisfaction of the Commissioner to have taken place in the course of inter-State trade or commerce within the meaning of section 3 of the Central Sales Tax Act, 1956 or in the course of import of goods into, or export of the goods out of the territory of India within the meaning of section 5 of that Act;