Because RAR is not natively supported by all operating systems, you will need specific software to "extract" or "unrar" the content within the file.
Right-click the Warunee.rar file and select "Extract Here" or "Extract to Warunee/" . Download Warunee rar
WinRAR is the standard tool, though 7-Zip is a popular free alternative. Because RAR is not natively supported by all