Option 1: Visit the nearest PRS booking center to change the boarding point Option 2: Get an unreserved ticket b/w VSG to MAO but be careful since you have said they are elderly.. They need enough time to move from GEN to the reserved coach within 2 minutes. Usually the seat will be empty b/w VSG and MAO.. It is better to check with TTE at VSG and get the permission from him to board the coach from VSG in case the BP is not changed officially. Unreserved ticket is mandatory since the pax will be travelling additional distance.