How to report if systems are registered to insights or not?

First of my apologies if this has been asked before. I did not find any answers when searching.

Is there a way to reconcile what is registered to the satellite 6 to what is registered to insights?

I see systems that are registered to satellite but I do not see them in insights.
For example I have 1500 systems in the satellite inventory.
I only see 975 in insights.
I want to find the ones that are not there and register them or install the code as needed etc.

Is there such a report ?
How can I generate it.
Something I can script or push from the satellite?