Whatever supports and assists with height control. Tie colas to string hang from ceiling, bamboo stakes, trellis net.. Tomato ring, doesnt matter.
Depends on the type of plant it may support itself fine depending on size and structure if you topped etc.
I use a plastic trellis net tied to corners of tent poles with ductape. Heres one tent of mine with nets. The second net I have yet to re hang or may not even be needed.