I don’t know about the selection procedure, but the function is to control the total H.S Exam. of that particular venue, starting from the collection of question papers, carrying the question papers with scott to the venue, opening the question papers after verifying the subject name at venue, watching the sitting arrangement in zig-zag way, watching the invigilation duty of the teachers, presence of medical team, keep in mind the time of opening the School main gate and close, watching for giving belles time to time, packing the answer script in proper way with seal and finally submit the answer script in defined spot. Also there are some paper works. For this you want to arrange a centre committee meeting.
Actually these are also the duties of center secretary and center in charge. All of them will help you. Council nominee also will help you. As far I know generaly an AHM/ senior asstt teacher will be the center supervisor of the school.