Section 250 (5) of the NYS Vehicle and Traffic Law says:
As used in this section, the term "resident" shall mean domiciliary, that is, one who lives in this state with the intention of making it a fixed and permanent abode. It shall be presumptive evidence that a person who maintains a place of abode in this state for a period of at least ninety days is a resident of this state.
To live in a house, a home, an apartment, a room or other similar place in New York State for 90 days is considered "presumptive evidence" that you are a resident of New York State. A police officer can use this as evidence to issue a traffic ticket if you drive in New York State without a New York State driver license or vehicle registration.
A judge considers the law and the evidence of your intent and decides if you are a resident of New York State. If you pay taxes or your children attend school in another state, a judge considers these facts to decide if your intent is to make New York a "fixed and permanent" residence. According to this law, students from other states or from other nations who attend school in New York State are usually not considered residents of New York. DMV does not decide if you are a resident of New York State, if you must get a NYS driver license, or if you must register your vehicle in New York State.