TurboTax does this automatically when you enter the Form 1099-R reporting the distribution that was rolled over. If more than one notation is needed on the line then TurboTax will put the notation "STMT" next to the line and will provide the multiple notations on a separate statement.
If you don't see the notation, revisit the Form 1099-R entry section and make sure that you have answer the questions appropriately to indicate that you rolled over the distribution. You can also try deleting and reentering the Form 1099-R reporting this distribution. Also, TurboTax will not report as rolled over any distribution that is not eligible for rollover, such as an RMD.
If you are still not seeing the ROLLOVER notation, please provide here details:
What is the code in box 7 of the Form 1099-R provided by the payer?
Is the IRA/SEP/SIMPLE box marked?
Was any part of this distribution an RMD?
