Generally the process of installing stuff from archives on Unix-likes is:
1. tar -zxvf (v optional, for verbose).
Depending on contents of package and what you want to do go to either 2A or 2B.
2A. Copy the binaries in the archive to some place from where you want to use them (like /usr/local/bin/) or just run them from where they are. In your case, you have the binaries rar, unrar and rar_static (linked statically to not require dependencies).
2B. If there were no binaries or you want to compile yourself, generally do:
./configure (not in this specific case since there is no configure file, there generally is though)
make
make install
So yeah. You have the binaries which you can run by just just typing in the terminal, or copy to some place included in your PATH environment variable such as /usr/local/bin so that you can then run them by just typing their name (like: unrar )
Originality said:
Having WinRAR helps as a general 'one fits all' archive manager.
The guy is running Ubuntu (as can be seen from any of his other topics apart from him stating it in the OP of this thread) so that's pretty irrelevant. Also 7-zip has the benefits of being less bloat and completely free over Winrar, is there any reason to use Winrar over 7-zip?