There's no direct support in form of some magic class or something and i don't think that it belongs into jPCT. It's a 3D engine, not a game engine. However, it doesn't prevent you from using any physics engine you like. You only have to do the mapping between the different coordinate system. The wiki contains a section about using JBullet with jPCT. It's the same thing for jPCT-AE.
For simple collision detections, jPCT offers everything you need out of the box.