Updating Resident Evil 6 on the Switch is a straightforward process:
Note: Always ensure that the Region Code (USA, EUR, JPN) of your update NSP matches the Region Code of your base game file, or the Switch operating system will fail to apply the patch. Key Improvements in Recent Resident Evil 6 Patches resident evil 6 switch nsp update link
Subsections of the patch notes dedicated to network code improved the stability of online Mercenaries matches and campaign co-op. Decoding Switch File Formats: NSP vs. XCI Updating Resident Evil 6 on the Switch is