Reply an email from a potential professor?
This is a positive response in that you can apply to take the entrance examination and you can also apply for a scholarship.

There is no automatic position granted or stated for you, so you have to follow the enrollment process for entry in Fall 2021.

You don't have to reply to this except perhaps to say "thank you for the information, I will (or will not) be applying for admission for the fall 2021.

Up to you if you will apply.