PURCHASE OMMISSION

Last date to claim itc for Financial year 2017-2018 is 30/9/2018 so cannot be claimed now.

The last date to claim ITC for the FY 2017-18 is gone now. The due date to claim ITC for FY 2017-18 was extended by CBIC till the due date of filing Return for the month of March 2019 ( i.e. 20th April 2019 ) vide Removal of Difficulty Order (ROD) No. 2/2018 - Central Tax, dated 31st December 2018.

Hence the credit is lapsed now...

Where such ITC is not claimed by such person in respective month, the same would be claimed by such person at any time upto the due date of filing return for the month of september following the end of the financial year to which such invoice pertains or before filing annual return by the recipient. Hence you are unable to claim ITC in this case.