How to select suitable area of low voltage cables? Or what are the "steps" to select suitable area of low voltage cables?

LV cables are basically 300/500 rated cables. Some are classified powerlimited like the fire cable for instance. So the first thing is the voltage your system is operating on. Second is the type of circuit(is it power limited like fire panels). Thìrd is the application environment , that is to say if outdoor or indoor. With gore cables we use fplr for raisers, ph30 in the floor and fplp in pleanums. So in general we may say, 1. The operating voltage 2. Type of system 3. Environment 4. Application ( like if for fire alarm check relevant sections of nfpa 72 and NEMA) Hope it answers your question