What is the ruling on lying to the student tuition assessment committee to reduce tuition fees, and what is the ruling on the money earned after graduation as a result of that?

Your work is permissible if it is lawful and performed as required. However, you must guarantee what was reduced from the tuition fees due to the falsehood by paying the reduced amount to the university. If that is not possible, then it should be spent on general Muslim welfare or given to the poor and needy.