The rate of tax on the sale of goods subject to levy of tax shall be zero when such goods are sold -
(a) in course of inter-State trade or commerce ; or
(b) in course of export out of the territory of India; or
(c) to a dealer having business under -
(i) a SEZ; or
(ii) a STP; or
(iii) a EHTP; or
(d) to an EOU