Folding one's hands in the last rakaat of the sunnats of fajr while sitting and performing salaah

If one only folded one's hands and then realized and one did not commence reciting the qiraat, then one should immediately place one's hands on one's thighs, recite the tashahudd, durood and dua and then complete one's salaah. Sajdah e sahw is not compulsory. However, if one commenced the recitation, then sajdah e sahw will be compulsory at the end of the salaah.

Note: The law of the two sunnat e muakkadah of fajr is different from the other sunnat e mua'akkadah salaah. The sunnat e muakkadah of fajr can only be performed sitting if one is unable to stand.

And Allah Ta'ala (الله تعالى) knows best.