Just 24 hours after iOS 10.2 beta 7 dropped and three days following macOS Sierra 10.12.2 beta 5, Apple on Thursday issued a sixth beta of what would become the second major update to macOS Sierra. macOS Sierra 10.12.2 beta 6 (build number 16C63a) is now available to registered developers.
The update can be deployed via the Mac App Store's Updates tab on Macs which are registered with the Apple Developer Program. The full installer is on Dev Center.