Both are belongs to vendor return
1. 122 - return to vendor -total consignment - return total received gr qty
Migo - return delivery with 122- j1is - credit memo
2. 161 - here you have to crate the return po. return to vendor for partial qty.
after po- gr - j1is-credit memo
Both of them are used for return of shipment to the vendor. However, the purpose of using is completely different. With Movement Type 122, you will have to post your GR reversal with reference to the original GR document number while 161 does not require such original GR document number but the return PO. Therefore, the 161 movement type is only used when you are not able to remember/identify the original GR document number for cancellation.