Open only the first part ( .part001.rar or just the .rar file if numbered differently) using your software.
This is the 6th part of a large file that has been split into smaller, manageable chunks (likely 500 total, or a 500MB+ set) to facilitate easier downloading or sharing [1]. 500.part006.rar
Here is the essential information regarding this type of file: Open only the first part (