This is a "Scene" release. The .part1.rar suffix indicates it is the first segment of a multi-part compressed archive. You would typically need all parts (part1, part2, etc.) in the same folder to extract the full game files.
Downloading files from unofficial sources like "SKIDROW" uploads on file-sharing sites carries significant risks, including malware, ransomware, or trojans bundled with the installer.
If you're interested in playing the game safely and supporting the developers, it is available on official platforms: Pro Cycling Manager 2021 on Steam Epic Games Store: Available via the Epic storefront.
