1. GRN can not be deleted if any transaction is made against it like Purchase Invoice or material Issue.
2. If Inspection is required in GRN and Intimation and Inspection Entry are done. Then You have to create Inspection Cancellation, then only you can delete GRN.
To cancel the inspection
Go to Utility Inventory Cancel Inspection (IMIC)
You can check the transaction in lot transaction report
Go to Reports Inventory Reports MIS Reports Lot Transaction or On Date Lot Transaction