International data transfers

I work for an institution which has spread out in xyz countries. We collect personal information of participants/individuals who register for our course with regards to yoga and mediation. As we are spread out in various countries and we have to transfer personal data as participants can enroll for courses once they are a member of the institution in any country. So we wish to keep a record where each individual has taken courses and based on points system they can avail discounts for other courses. Since data would be transferred from one country to another how to safeguard personal information and not be in fault with any data protection laws worldwide.