ITC claim as per purchase Rs. 18974

Ask your supplier file( upload invoices) IFF /GST R1 which ever applicable for fim for that month.

In addition to reply by Mr Hegde , For input tax credit as per section 16(2) of the CGST act 2017 , you have to fulfill following conditions
1) You must have valid tax invoice and correct GSTN of supplier
2) You must receive Goods or services .
3) Supplier must pay tax collected from you to GOVT account .
4) you must file return .
Also same ITC should not be under block credit as per section 17(5) of the CGST act 2017.

You need to find out if any invoice is pending to be uploaded by the seller.

In any case, if such return is pertaining to April or May, you may claim ITC on the basis of invoice because rule 36(4) has been relaxed for Apr and May.