Events (click, open etc.) and error reports and some compressed file information will be collected. This is for application health and investigate problems.
UnRar cant access any file or folder in your device without you select it. Be relax in this issue.
UnRar does not work in background without you dont have information. It does not use any system resource ( CPU, GPU, Ram, Hdd, Ssd, Internet) for data mining, crypto currency mining or other aims.