Most objects are not able to float in midair. What must be occurring for these rings to float instead of fall

magnetic force

Explanation:

A magnet is defined as an object that can attract other objects that are made of iron. Magnets also repels or push away other magnets. Every piece of magnets have two poles namely, a south pole and a north pole. When one magnet comes near another magnet, it exerts a magnetic force on the other magnet. This force can be attractive force or repelling force depending upon the poles surface of the magnet that are close to each other.

Like pole repel each other while opposite poles attract each other.

In the context, the rings of magnet are floating in the air because there is a magnetic force that is repelling the like surfaces or the like poles of these magnetic rings.