If you are looking at the collection often shared in enthusiast communities like Gearspace , it likely contains:

: Always scan .rar files with antivirus software before extraction to ensure they do not contain malicious scripts.

: If you receive an error while opening, you can try the "Repair archive" tool built into WinRAR. How To Open, Create, and Convert RAR Files - AVG Antivirus

To "look into" or extract the files from a .rar archive, you will need specific decompression software: : Install WinRAR, 7-Zip , or p7zip (for Linux).

: Occasionally includes text files (.txt) detailing the patch names or bank order. How to Access the Content