Is it necessary to repeat ablution when washing the right foot three times and the left foot twice?

It is better to wash the left foot three times, but washing it twice does not invalidate the ablution; rather, it suffices. The obligation in washing the limbs is once, and three times is a Sunnah. Authentic hadiths have been reported showing washing once, twice, and three times, and this variation is an indication that all of these are permissible.