DeepSkyStacker is not available for Mac but there are a few alternatives that runs on macOS with similar functionality. The best Mac alternative is Siril, which is both free and Open Source. If that doesn't suit you, our users have ranked eight alternatives to DeepSkyStacker and four of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to DeepSkyStacker are Starry Landscape Stacker (Paid), PixInsight (Paid) and Regim (Free).
Regim makes some processing steps that are unique to astronomical images a bit easier. These steps are calibration (dark and flat), deblooming, registration, combination, color calibration, gradient removal and some more.