You don't designate your charitable donations to one state or the other. Enter all your donations in the federal section of TurboTax. TurboTax will handle them appropriately on each state tax return.
The full amount of your donations goes on your New York tax return and is deducted in calculating your taxable income. The calculation of the New York tax apportions your taxable income, after deductions, based on the percentage of your income that is from New York.
There is no deduction for charitable donations on the New Jersey tax return, so no amount of donations will appear on that return.
