There are 7 menus, each one can modify a zone of the map and make gangs appear. How to open the menus:
F9 + 8 : Opens Ballas menu
F9 + 7 : Opens Vagos menu
F9 + 6 : Opens Aztecas menu
F9 + 5 : Opens Mafia menu
F9 + 4 : Opens Triads menu
F9 + 3 : Opens SF Rifa menu
F9 + 2 : Opens Da Nang Boys menu

If you open more than 1 menu at once you might crash the game, so do it separately.

How to use:
When you open the menu, choose a zone. Depending on which menu you're using, members from that gang will appear in that zone. Only ballas and vagos can change the color of the zone and start gang wars.

I included a mod that lets you spawn gangs from all the ones I mentioned up there, but only ballas and vagos will help you starting wars.