Estoy listo para ordenar used in Mexico?

Estoy listo para ordenar used in Mexico?
 

Is it true in Mexico its common to say in a restaurant Estoy listo para ordenar?

Not usually.

The waiter is likely to ask you if you're ready to order after you've read the menu: "¿Está listo para ordenar?"/"¿Están listos para ordenar?"
But the waiter could also say "¿Puedo tomar su orden?" (May I take your order?)/"¿desea(n) ordenar?" (Would you like to order?)...

A customer would be likely to say "¿Me puede tomar la orden por favor?" (Would you take my order please?) / "¿Puedo ordenar?" (May I order now?)...