Yes, it may affect the electives available to you. The MSc programmes at RSM are designed to be completed within one year. The elective registration process therefore prioritises students who need electives to complete their programme within the nominal study duration.
Students who need additional time to complete their studies are also facilitated, but may have fewer electives to choose from, depending on the availability of places after the first registration round(s). In previous academic years, students in this situation have generally been able to find available electives to fulfil their remaining requirements in order to graduate.