Money you take out of a retirement account is reported on a 1099R which you will receive (or import) in late January/mid-February for your tax return. You simply enter the 1099R into the tax software and then answer a question in the software as to whether the distribution was an RMD.
To enter your retirement income, Go to Federal> Wages and Income>Retirement Plans and Social Security>IRA 401 k) Pension Plan Withdrawals to enter your 1099R.