HI,
This happen most of the time for e.g. Material is defined as Raw Material at the time of J1ID and while doing J1IEX it has been defined as Tools / Assets.
In this case either you can
1. Reverse the excise document and GRN.
2. Do fresh GRN and do excise posting through transaction code J1IEX.
3. You can update values in J_1IGRXREF table.
I would suggest you to reverse the earlier documents and do fresh GRN and avail credit on the same.
Regards,
Tejas