what is the admission ticket to CIS

Hi, I saw lots of parents here agree with that ESF kinder is an admission ticket to ESF primary. Here comes my question, what is the admission ticket to CIS?

parents here didn't mention CIS quite often. So I bring my question up here.

We live in Hung Hom. And my son was born in March 2009. most of the time, he speaks mandrin, and knows a little bit about English, words and simple sentences.

Now he's in an int'l pre-school, led by a NET and an assistant