I have added students under My eLearning tab, when will it reflect on Moodle?

The student list on Moodle will be automatically updated according to SIS.
Moodle gets the updated enrollment records from SIS twice a day (10:00 and 16:00 under normal situation).

Once teacher add the class of student in HKU Portal, they will see the student enrollment status is "To be added". The students will be added to the course in an hour.