What is the ruling on taking a goodly loan designated by the university for the purpose of completing studies and marriage, with the intention of repayment, given the father's unawareness and his desire to postpone the marriage?

Borrowing is permissible, especially when needed. The Prophet, peace and blessings be upon him, used to borrow. If a son needs to get married and longs for it, and he is able to marry by taking out a loan, the father is not allowed to prevent him, because doing so would cause him harm and open doors to forbidden acts, especially in a mixed university environment where temptations are numerous.