I believe they are inhibited in that if you did have an active RA as you descend through the inhibit height it would stop giving commands. (Good question though, I haven’t thought of that.)
“Increase Descent Resolution Advisories are inhibited below 1450 feet AGL.
• All Resolution Advisories are inhibited below 900 feet descend-ing or 1100 feet ascending.
• All TCAS II audio warnings are inhibited below 900 feet Radio Altitude on approach and up to 1100 feet Radio Altitude on departure.”
Honeywell Collision Avoidance System Pilot's Guide
TCAS II CAS 67A, 2004