If you are looking for the original post or source to download the remaining parts, you may need to check the specific forum, private tracker, or index where you found this file, as these archives are rarely hosted as standalone files on the public web.
To extract the contents, you must have all parts of the archive (e.g., part01 through the final part) in the same folder. MNFTS01WEB18.part05.rar
The "WEB18" portion suggests a web-rip or digital release from 2018. If you are looking for the original post
You can use tools like WinRAR or 7-Zip to open the .part05.rar file. Once you open the first part, the software will automatically join the others to reconstruct the original file. MNFTS01WEB18.part05.rar