If you want to play Unrailed! with updates, the safest way is to buy the game. It frequently goes on sale for under $10. The co-op experience is worth it, and you avoid malware risks.
Given the phrasing, this likely refers to a scene release, patch, or crack for the game Unrailed! — specifically an (Nintendo Switch package), a RAR archive (numbered 1011), and a "link" that needs to work. The "39link39" might be obfuscated text or a typo for <link> or 'link' in markup.
Files from unofficial sources are often split or damaged. If the 1011.rar fails to extract with WinRAR/7-Zip, the link is dead or the file is broken.