If you have an existing perpetual or older license, you may not want to pay for a new subscription. Prerequisites for Installation
If you need to get this older version running, please share your and current macOS version so we can check if it is compatible. Download Adobe Premiere Pro Cc 2015 For Mac
Double-click the Install icon inside the folder. If you have an existing perpetual or older
For users with legitimate Creative Cloud subscriptions who need offline installers, some third-party resources have archived the original CC 2015 installer packages. One such installer for Mac is available as "Creative Cloud_Install.pkg.zip," which contains the complete installation package. The file size for the Premiere Pro CC 2015.3 v10.4.0 installer is approximately 1.13 GB, making it manageable for most internet connections. For users with legitimate Creative Cloud subscriptions who
If Adobe After Effects CC 2015 and Premiere Pro CC 2015 cannot communicate via Dynamic Link, verify that both apps are updated to their exact corresponding versions (e.g., Premiere 9.2 and After Effects 13.7). Missing minor updates breaks the shared background render cache. Missing Audio Codecs (Dolby Digital)
If you do manage to find an installer, ensure your Mac meets these original 2015 specs: Can't download certain previous versions - Adobe Community