In this case you should show ITC in para 8C of GSTR-9 only if you have received the goods in 2017-18.
Your attention is invited to instruction 8C of GSTR-9 which reads as under: –
“Aggregate value of ITC availed on all inward supplies … received during July 2017 to March 2018 but credit on which was availed between April to September 2018 shall be declared here. Table 4(A)(5) of Form GSTR-3B may be used for filling up these details.”
Further explanation to section 16(2) reads as under: –
“Explanation. – For the purposes of this clause, it shall be deemed that the registered person has received the goods where the goods are delivered by the supplier to a recipient or any other person on the direction of such registered person, whether acting as an agent or otherwise, before or during movement of goods, either by way of transfer of documents of title to goods or otherwise;”
So if the transporter is acting as your agent, you may say that you have received the goods through your agent at the time of delivery of goods to the transporter and accordingly may show the ITC in 8C of GSTR-9. In such a case, you should enter the purchase in March-2018 itself although ITC may be claimed later in April-2018.
Disclaimer: This is only our opinion and you are free to take a different view.