Microsoft recommends always installing the latest Cumulative Update for SQL Server 2016, as it bundles all previous ssis6 upd fixes.
"SSIS6 UPD" appears to refer to a specific software update or firmware package associated with the hardware platform . While specific technical documentation for this exact string is often proprietary or internal to specific manufacturers, What is SSIS6 UPD? ssis6 upd
Comparing Version 6 features with the updates. Changing the version of an SSIS package. - SQL Studies ssis6 upd
Right-clicking the SSIS Packages node and selecting "Upgrade All Packages" is the fastest way to batch-update connection managers and task XML Upgrade Guide . ssis6 upd