You have to file a Pennsylvania nonresident tax return and pay Pennsylvania tax on the gain from selling the rental property. Since you are a North Carolina resident, North Carolina will tax all of your income, no matter where it is from. But you will get a credit on your North Carolina resident tax return for part or all of the tax that you pay to Pennsylvania.
In TurboTax, prepare your Pennsylvania nonresident tax return first, then your North Carolina resident tax return, to make sure that the credit is calculated correctly.
