I have an Aurora as well, but not R4. If it doesn't matter which one as long as Aurora, then yes. Last I checked, there was 2-3 more internal slots. Plus, you can add externals as well
So far, I have 1TB that came with, 1 TB installed internal, 2 TB external attached, and 1 TB external attached.
Though, I do not know if it can handle an internal of 2TB or more. It should be able to handle a 2 TB one, but you have to make sure it fits into the harddrive holding containers. Either way, make sure you have the appropriate SATA cables. Plus, you can always look up the manual.