As per Notification 10 IGST ( R), under S.no.10 Services supplied by a person located in non- taxable territory by way of transportation of goods by a vessel from a place outside India up to the customs station of clearance in India is under RCM As per Section 13 (9) , IGST Act 9] The place of supply of services of transportation of goods, other than by way of mail or courier, shall be the place of destination of such goods. Note : Notification 10 IGST : Defines Services on Which RCM is applicable
Freight value will be 10℅ of CIF Under RCM , self invoice has to be raise &. According to Rule 36 , invoice issue in accordance to provision of section 31 cgst act , is a eligible document to take ITC.
But As your outward supplies are exempted the same has to be reverse as per section 17 cgst act