Hi,
Yes, you can place any RSID you'd like in the report suite field within DTM. The dropdown will auto populate with RSIDs that are connected to the same Experience Cloud Organization if your user is authenticated and linked to the Experience Cloud.
With that said, you should be careful with cross Experience Cloud deployments as the Marketing Cloud ID service is tied back to the Experience Cloud org that your solution is linked to. For example, I would not recommend using an RSID that belongs to a different Experience Cloud org if you have the ID service tool deployed on the same DTM instance. This is because the ID service tool was likely deployed with the Experience Cloud Org ID that is linked to the DTM company, not the Experience Cloud Org ID that is linked to the other Analytics company where the report suite belongs.
I know this can be a bit confusing so please let me know if you have additional questions.
Cheers,
Jantzen