To open and extract a .rar file on an Apple OS X system, you can use a third-party utility such as The Unarchiver or WinZip.
The Unarchiver is a free, open-source utility that is available in the App Store. It can be used to open and extract a wide variety of archive formats, including .rar files.
To extract a .rar file using The Unarchiver, you can simply double-click on the file in Finder. This will open The Unarchiver and extract the contents of the file to a new folder in the same location as the .rar file.
Alternatively, you can use the WinZip utility to open and extract .rar files. WinZip is a paid utility that is available from the App Store. It can be used to open and extract a variety of archive formats, including .rar files.
To extract a .rar file using WinZip, you can double-click on the file in Finder or right-click on the file and select "Open with > WinZip". This will open the file in WinZip and allow you to extract the contents to a specific location.
For more information about The Unarchiver or WinZip, you can consult the documentation for these utilities or visit their websites.