Is it true if one does IB board in junior and senior high school,they are not required to take Advanced Placement Courses?
It would depend on your school. Some schools allow students to take a couple of IB courses without the full Diploma some do not. At my Ds school, the full IB Diploma students have also taken some AP courses as well. No one at her school is required to take either, they could just take honors or regular courses.
Junior year most IB Diploma kids take up to 7 courses- so it leaves little room to take AP.