For detailed technical notes and known issues specific to this build, refer to the Pro Tools 12.8.3 Read Me (PDF) provided by Avid .
: Version 12.8.3 is specifically documented for macOS 10.11.x (El Capitan) , 10.12.x (Sierra) , and 10.13.x (High Sierra) .
Download the and follow the standard installation process. Key Features and Improvements
Check your to ensure your license's "Release Limit" date is after December 19, 2017.