Getting a "free" version of Adobe Photoshop CC 2015 for Mac through unofficial channels is highly risky and generally discouraged. Since Adobe transitioned to the Creative Cloud subscription model, standalone or perpetual free versions of this software no longer legally exist Availability and Official Status Adobe Discontinuation
If you previously purchased a that included CC 2015, or if you have a Volume License from an employer that still owns seats, you may be able to download the installer from your Adobe account. adobe photoshop cc 2015 download mac free