Winzip 7 is a free download and converts .rar files :)

RAR are a type of Zip file.

You would need a program to open the RAR zipped files.

The RAR zip file should contain different design formats and the pes file may be there inside the RAR file.

If the pes design format is not inside the RAR zip file then you would need a conversion program to convert one of the design formats inside the RAR zip file to the Pes format you need.

Wilcom True sizer is a free program that should do the conversion to pes design format for you but you still need a program to open the RAR Files.

There are a couple to programs that may be free to open RAR Files.
WinZip 7 will open the RAR zip.
I am not sure if it is a free program or if you have to purchase it

Perhaps someone else will know what free programs will open RAR zip files.

EastWitch2

Embird Basic will also open and convert RAR files...I believe you can download a free trial from the Embird website if you want to try it first...

Recommended by evajungerman here a while ago. Super easy to unzip any files. Will even do a batch unzip, nice when you have a lot of files to go through. I use it a lot.
Jo