Yes—Bhavanavasi devas can interact with other celestial beings in their own realm. In Jain cosmology, they live together in their devaloka and have mutual association, but their interactions are according to their own subtle celestial existence.

Regarding ordinary people on earth, they generally do not interact freely like humans do. If they appear or influence events, it is only in special circumstances, according to their karmic position and celestial nature.

So in short:

• With other devas: yes, they can interact.
• With humans: only rarely and in a limited, special way.
• Their life is not like human social life: it is more subtle and bound by their celestial birth and karma.