If you are looking for the official version of the game, it is available on platforms like Steam and GOG, which handle the installation process automatically for you.
It looks like you’re referencing a specific archive file for the game , likely part of a larger multi-part download (v1.04.02). ANNO.Mutationem.v1.04.02.part2.rar
Do you have the of this archive, or are you having trouble with an extraction error ? If you are looking for the official version
Multi-part archives (like .part1.rar , .part2.rar , etc.) require every single segment to be present in the same folder. ANNO.Mutationem.v1.04.02.part2.rar
Once you have all pieces, right-click on part1.rar and select "Extract." Your extraction software (like WinRAR or 7-Zip) will automatically pull the data from all subsequent parts to rebuild the full file.