What's the best way to handle this scenario: Retailer returns 1000 units of Item A. The return includes ITEM A from 3 different sales orders. Would we be generating 3 different RMA's or should we do an inventory adjustment? How do we handle the actual refund part within netsuite?

Each

Sales Order

should have a

Return

or

Accept Return

button to generate a RMA. That would be the native process that properly ties the returned quantity to each Sales Order and handles all the underlaying inventory and GL impact. Short Answer: 3 returns (one per each Sales Order).