Is it permissible to use mediation to be accepted into postgraduate studies, knowing that the questioner will exert her utmost effort in her studies?

If all applicants for the test receive equal opportunities and preference is given based on knowledge and experience, then it is not permissible to use intercession (wasta) to put you ahead of someone more deserving, because that involves cheating and deception. However, if applicants do not receive equal opportunities and preference is given based on nepotism and partisanship, then it is permissible to use intercession (wasta) to prevent injustice from befalling you.