Oxford University requirements?

If you wish to apply to Oxford University, EITHER A-levels or the IB would be perfectly acceptable. To make a really competitive application you would need to gain AAA at A-level, or 38-40 points in the IB (including the core points) with 6s or 7s in the higher level subjects. There may be specific subject requirements too, depending on which subject or subjects you wish to study. You can check at http://www.ox.ac.uk/undergraduate/courses/courses_and_entrance_requirements/index.html

As for the question about your school, Oxford tutors are really looking for the best applicants, irrespective of their background. They will be interested in YOUR academic ability and your passion and commitment for your course, not in the school you have attended. (However, tutors will take your educational background in to account, and are likely to be particularly impressed if you have managed to achieve top grades at a school or college where top grades are rare.)

If you would like further information, you are welcome to contact the Admissions Information Centre at Oxford University. Just see http://www.ox.ac.uk/admissions/undergraduate_courses/finding_out_more/index.html for further details.