If someone is unsure whether they have completed four or five Rak'ahs, should they sit, recite the Tashahhud and Salam, then perform one Rak'ah of Salat al-Ihtiyat while standing, or two Rak'ahs while sitting?

TashahhudSalah (Prayers)
If someone is unsure whether they have completed four or five Rak'ahs, should they sit, recite the Tashahhud and Salam, then perform one Rak'ah of Salat al-Ihtiyat while standing, or two Rak'ahs while sitting?
Sayyed Mohammad Al-Musawi, Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to... Answered 8 hours ago

In case of the doubt between four of five Rak'ats,nyou should take it as four and recite Tashahhud and Salam, then perform two Sajda of Sahw. There no Salat al-Ehtiyat in this case.

Wassalam.