I worked in a residency office for a state school. Some schools allow you to receive residency after living in the state for 1 year, and with others you will never be a resident unless you spend a year (365 days) working full-time, not going to school, and just being a normal resident of the state.
Most all fellowships / assistantships will waive your tuition anyways, or at the very least bring you to in-state rates.
Do NOT go to a school if you have to pay full out-of-state tuition. It's not worth it. You shouldn't be paying anything for grad school, and having to pay full out-of-state tuition is insane and put you in over $100,000 of debt.
