Serato DJ Lite officially requires macOS 10.13 (High Sierra) or later. The software relies on modern audio frameworks, Metal graphics acceleration, and up-to-date USB driver protocols for DJ controllers. Mac OS X 10.6.8 lacks these components, so even older versions of Serato DJ Lite will not install or function properly.
To DJ on OS X 10.6.8, you must use legacy versions of Serato software: serato dj lite for mac os x 10.6.8
and subsequent early versions are the correct choice for OS X 10.6.8. Serato Scratch Live (Legacy Alternative) Serato DJ Lite officially requires macOS 10
Compatibility on such an old OS depends heavily on your hardware drivers: Metal graphics acceleration