Hi........

i want to know that what is the Use of X & Z restraint in spring can modeling with friction. as i have observed that these supports are act as Guide & limit & increase that nozzle load.

I'm not sure what you're looking at.
When modeling friction around a spring can, the horizontal restraints have connecting nodes. This modeling artifice allows the spring load to serve as the normal load for friction

In CII Application Guide, page 76, "Modelling spring cans with friction", you are considering RX, RY, RZ restraint at 15-20 rigid element (can length).

Is it ok to ignore these restraint?

As normal, my practice is same as above mention from Dave (without RX,RY,RZ)

Regards.