Part 3: How to Open A RAR File On Mac.Use the -k switch if you want to keep the CBR file. If you specify a directory, it will convert every CBR file inside it. You can install it easily on Mac OS X with homebrew by using brew install unrar. If you’re looking for a single app or utility that can handle all of the file formats mentioned above, The Unarchiver is the one that can do it all. Open ZIP, RAR, TAR, BIN, And EXE On Mac With The Unarchiver. Luckily, there are multiple ways to add support for the aforementioned file formats to your Mac.