As a legacy version, Pro Tools 12.8.3 is no longer the current version available in the main Avid storefront. To download it, you must have a registered Avid Master Account with a valid Perpetual or Subscription license.
Pro Tools 12.8.3 is a point release update to the Pro Tools 12 series, which was first introduced in 2014. This update brings several bug fixes, performance improvements, and new features to the software. Pro Tools 12.8.3 is compatible with macOS High Sierra (10.13.6) and later, making it an excellent choice for Mac users. Pro Tools 12.8 3 Mac Download
recommends avoiding 10.13.4 due to known CPU performance issues macOS Sierra (10.12.6) Mac OS X El Capitan (10.11.6) Hardware Requirements: Intel Core i5 or i7 processor. As a legacy version, Pro Tools 12
16GB minimum (32GB+ highly recommended for professional projects). Disk Space: 15GB for a full installation. Authorization: Requires an How to Download Pro Tools 12.8.3 This update brings several bug fixes