I’ve been living in California for 5 years (almost 6years now) but still isnt a resident. If I get into UCs or other public school and then become citizen or permanent resident in that state, do I pay in-state tuition?
If you become a permanent resident of California, yes you would pay in-state tuition. Being a US citizen, without state residency, will not get you in-state tuition.
Also do an internet search on DREAM Act, if you intend to apply to college before you get a green card.