Can fasting the six days of Shawwaal be done on Mondays and Thursdays?

Praise be to Allah

Yes, there is nothing wrong with that, and there will be
recorded for you the reward of fasting the six days (of Shawwaal) and of
fasting on Mondays and Thursdays. 

Shaykh Muhammad ibn ‘Uthaymeen (may Allah have mercy on him)
said: 

If it so happens that the fasting of these six days is done
on Mondays and Thursdays, then the person will attain the reward of fasting
on a Monday with the intention of attaining the reward for fasting the six
days, and the intention of attaining the reward for fasting on a Monday or
Thursday, because the Prophet (blessings and peace of Allah be upon him)
said: “Actions are but by intentions, and each person will have but that
which he intended.” End quote. 

Shaykh Muhammad ibn ‘Uthaymeen (may Allah have mercy on him).