how and what kind of phyisics simulation to insert ?

hello 

i often use creative experience to develop VR Scenarios 

there is an option saying that i can insert Existing Physics Simulation (take a look on a picture)

I encountered a problem while inserting Physics Simulation

i dont know exatly what kind of physics simulation to insert because i tried to insert (robotic simulation ,ergonomic simuation .... but still not possible to do it i dont know )

Any help is appreciated! thanks