the minimum gcse grades i would say would be 5 A's and 4 or 5 B's but the vast majority of applicants will have better grades than that though dont get too worried about gcses, unis place alot more emphasis on AS levels, work experience, personal statement and to a lesser extent predicted a level grades!as long as you get good gcses and get AAB or better at as you will be fine!make sure you get plenty of varied work experience!good luck