If it asks for a password, it is usually provided where you downloaded the file from (e.g., a forum post or YouTube description). To give you the exact content, I'd need to know: Where did you download GCRP.rar from? Are you looking to edit the code or run the server ?
Once you extract it, I can help you understand specific files! GCRP.rar
Use software like WinRAR, 7-Zip , or WinZip to right-click and "Extract Here" to view the contents. If it asks for a password, it is