Yes, there is a regulation and it can be obtained through the Deanship of Student Affairs page on the university website.
Yes, the student is entitled to object to this action; the student should not take more than two exams on the same day, except in special cases.
Yes, according to the Disciplinary Bylaw, a disciplinary action will be taken against the student if they cheat in the exam, try to cheat, or breach the exam instructions and rules.