The second public beta version of OS X El Capitan 10.11.6 is now available for members of Apple's Beta Software Program. Members will find the new version in the Update section of the Mac App Store.

OS X El Capitan 10.11.6 Public Beta 2 arrives for testers

Details are still light on the contents of OS X 10.11.6, though it's likely to fix some bugs. At this stage, the update is unlikely to carry major new features, with attention turning to the next major version of OS X, likely 10.12.