An owner of a college of Education lease the school to me to run for three years based on his health issues. Is it right for him to still hold on to the certification of students?

Your question isn't clear. Holding on to the students' certificates you mean? Well, if you are running the school on his behalf for valuable consideration, you can request the students' certificates from him. If he still refuses after your demand, he should understand that his actions are impinging the success of his school.