Sir,
According to Section 16 of IGST Act, 2017 "supply of goods or services or both to a Special Economic Zone developer or a Special Economic Zone unit are zero rated supply." A registered person making zero rated supply to a Special Economic Zone developer or a Special Economic Zone unit shall be eligible to claim refund as under: -
(a) he may supply goods or services or both under bond or Letter of Undertaking, subject to such conditions, safeguards and procedure as may be prescribed, without payment of integrated tax and claim refund of unutilised input tax credit; or
(b) he may supply goods or services or both, subject to such conditions, safeguards and procedure as may be prescribed, on payment of integrated tax and claim refund of such tax paid on goods or services or both supplied.
However, conditions, safeguards and procedure for claiming such refund are yet to be notified.
As far as supply of imported goods to EOUs, you have to pay appropriate gst utilizing the ITC of IGST paid on imported goods (that is, CGST and SGST if your warehouse and receiver of the supply are located in the same state or IGST if your warehouse and receiver of the supply are located in different state). If the EOU utilise the goods supplied by you in the manufacture of export goods then the EOU can claim the refund of unutilised ITC.