Many community-created mods for the original trilogy or the Legendary Edition are distributed in .rar format. These often include .pcc (meshes/textures), .afc (audio), or .sfar (DLC) files.
If the archive contains a mod, it is often best to import it directly through a tool like the Mass Effect Modder (MEM) or the ME3Tweaks Mod Manager rather than extracting it manually. Mass-Effect.rar
Use WinRAR (official developer) or 7-Zip (open-source). Many community-created mods for the original trilogy or
Right-click the file and select "Extract Here" or "Extract to folder". Mass-Effect.rar
Because Windows and macOS do not natively support the RAR format, you will need a third-party utility:
Extractors for 3D modeling may use archives to store meshes and textures for use in external programs like 3ds Max. How to Open and Extract