1) Does the RMD amount show on your 1099? None of my 1099s show it and typically you have to calculate it, or get it from your investment company or financial advisor.
2) Is the RMD for the IRA greater than the distribution you received from it? If so, then you'll pay taxes not only on the distribution (which your investment company has probably taken out and will show on your 1099) but also on the difference (which TTax will calculate and create a form 5329 for). Unless of course, TTax has a bug in its software!
3) To answer your question, in TTax you should supply both the Distribution Amount and the Required Minimum Distribution for your IRA.
4) For an inherited IRA there are also considerations depending on the date of the death of the account holder; the 5 year rule and the new 10 year rule.
See https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-beneficiary
