If states taxes were withheld, the amount should appear in Box 12 of the Form 1099-R, and entered into TurboTax as shown. The amount would then carry over to the State withholding section of your return.
You may want to re-visit the Form 1099-R interview section. You can do this by typing Form 1099-R in Search, clicking the Jump to form 1099-R link, then click Edit to review your entries.
