I have a RAR file in one drive. I'd like to move the content inside it to another drive.?

It does not really matter. If your RAR file contains millions of files, then, there is no point extracting it in your current drive and then move. So, I would suggest you move your RAR to the new drive and extract it from there.

one more option - don't move, just extract to the other drive.

Move then extract it works for me whenever I need to do so.

Hi, neither option is any worse or any better than the other. The only thing I would add though is that if the RAR file contains a huge amount of data and is likely to exceed the space left on the drive where the RAR file resides, move it to another drive with more space available before extracting but to be honest this is highly unlikely.

Cheers