Answer:
Subsidy ; Price Ceiling
Step-by-step explanation:
Subsidy is the financial assistance by government, to increase a good's availability at cheaper price, to people.
Price Ceiling is the maximum mandated price by government, at which a good or service can be sold in market.
Government giving every student a voucher to redeem at any school : Is a form of financial assistance, which reduces the price paid by students. So, it is an example of Subsidy
Government mandating no tuition fee above $6000 : Is specification of maximum mandated price at which a good or service can be sold. So, it is an example of Price Ceiling.