State tax filing

Yes, you can claim the entire IRA contribution against NYS taxes if your entire earned income was in NYS.  As you go through your NYS interview in Turbo Tax, you can allocate income and deductions as your NYS income and deductions. I will show you the screen in the bottom of this post where you will make that allocation.

Once the allocation has been made, the allocation will appear in Line 18 of the IT 203 and in Line 17 of the It-360.1 and columns A&B. Here is the screenshot that shows the screen where you may make the allocation.