Sounds like he will be a resident for both states, and you will take a credit in SC for taxes paid to another state. Following are rules for NY:

Can I be a resident of New York State if my domicile is elsewhere?

You may be subject to tax as a resident even if your domicile is not New York.

You are a New York State resident if your domicile is New York State OR:

• you maintain a permanent place of abode in New York State for substantially all of the taxable year; and
• you spend 184 days or more in New York State during the taxable year. Any part of a day is a day for this purpose, and you do not need to be present at the permanent place of abode for the day to count as a day in New York.