I know a homeschool student who got into PEA 2 years ago. He has adjusted well and is doing well academically there.
My suggestion is that since your child has been homeschooled, perhaps you should consider the following:
1) I suggest your child go to boarding school (not homestay) so that he will learn more social skills and how to interact with other students.
2) Find a school that is nurturing and understands what a student has to go through adjusting to boarding school life.
3) Talk to the schools when you are interviewing to find out more about how they help the child adjust to school life.