A code 6 in box 7 of the Form 1099-R will not add taxable income on your tax return. Was there an amount in box 2a? Were any boxes checked in box 2b?
TurboTax would have correctly entered the gross amount from box 1 of the Form 1099-R on the Form 1040 Line 5b and 0 on Line 5b as the taxable amount.