Erik Kostson
Ansys Employee

When we use applied by with a remote attachment for the point mass, then there are some option (behaviour), such as coupled, deformable and rigid.

The rigid would make that connection of the mass down to the frame rigid, while distributed or coupled would distribute the mass more to the nodes of the frame without adding the stiffness the rigid option does.

If you search for remote attachments and points online and in the help manual you will find quite a lot of info on that.
Their behaviours are similar to RBE2 (rigid -remote attachment) and RBE3 (distributed remote attachment).
All the best