Is an international student entitled to request a return ticket after completing his studies, knowing that he had already sold the return ticket allocated to him?

If the ticket is a conditional gift that can be reclaimed, then it is not permissible to sell it. However, if it is an absolute gift of ownership, then it is permissible. Regarding seeking assistance, if its presentation is legitimate and legal, then there is no harm in it. But if it involves deception or fraud, then it is not permissible, because what is forbidden to do is forbidden to seek.