Use the file command to confirm it is a true RAR archive.
Is this for a (e.g., PicoCTF, HackTheBox)? Do you have a password for the archive? What files are inside the .rar after you open it? REFLECTED.rar
Look for or Atbash ciphers (Atbash is a "reflection" cipher). Use the file command to confirm it is a true RAR archive