Open the folder containing Bakih22GraD18plRyV-V435.part01.rar (and part03).
Right-click only on the first file ( ...part01.rar ). Bakih22GraD18plRyV-V435.part03.rar
You cannot open or extract this file alone. You need all parts (e.g., .part01.rar , .part02.rar , .part03.rar , etc.) in the same folder. Open the folder containing Bakih22GraD18plRyV-V435
One of the parts was downloaded incorrectly. Re-download the part named in the error message. Bakih22GraD18plRyV-V435.part03.rar
Are you using or macOS (The Unarchiver) ?