For your convenience, here are the verified download links for GarageBand:
Some users have reported issues with GarageBand on Mac OS X El Capitan 10.11.6. Here are a few known issues and potential fixes: garageband mac os x el capitan 10116 download extra verified
Click on the tab (or your account avatar in newer App Store versions). For your convenience, here are the verified download
: These installers have expired security certificates. To make them work, temporarily change your Mac's system date to March 2012 in System Preferences before running the installer. For your convenience
OS X El Capitan 10.11.6 , the officially compatible versions of GarageBand are GarageBand 10.1.2 or the older GarageBand '11 (version 6.0.5)