If you only have .part1.rar and are missing the other parts, the extraction will fail. Ensure you have downloaded the entire archive set. To help you further, could you tell me: Where did you download this file from? Are you seeing an error message when trying to extract it? Do you have the other parts (part2, part3, etc.)?
Ensure you downloaded this from a trusted source to avoid malware or ransomware.
You cannot extract the contents of Npri_alpha045.part1.rar without the subsequent parts ( .part2.rar , .part3.rar , etc.).
Use tools like WinRAR, 7-Zip , or The Unarchiver (for Mac).
Ensure you have Npri_alpha045.part1.rar , Npri_alpha045.part2.rar , etc., in the same directory.