Are SEZ Units liable to pay taxes on their inward supplies? Who will be eligible for refund of taxes paid on supplies to SEZ

No. SEZ units shall not be charged with taxes for supplies made to them. In respect of supplies to a SEZ unit or a SEZ developer, the application for refund shall be filed by the –
(a) supplier of goods after such goods have been admitted in full in the SEZ for
authorised operations,
(b) supplier of services along with such evidence regarding receipt of services for authorised operations; as endorsed by the specified officer of the Zone.

(ICAI FAQ PUBLICATIONS 06-09-2017 REFUNDS : FAQ NO. 6)