If Part 3 is even 1MB smaller than the others (except the last part), the download is likely corrupted.

Are you getting a when trying to open it? Do you have the other parts of the archive?

Always scan .rar files with Windows Defender or VirusTotal before extracting, especially if downloaded from third-party forums or media-sharing sites. To help you further, could you tell me: Which PES version (e.g., PES 2021, PES 6) is this for?