Japan age restriction

I was born in 2007 in June just before cut off. This means I will be 17 in grade 12. Because Japan is age restricted, will I be pushed back, and will I have to redo a year?

Are you attending a Japanese or International School?

No, I am currently in an Australian private school, but I am possibly applying to become an exchange student in Japan so I will do my grade 12 year there.

about exchange program:
I expect that the 12th grade means you are in the final grade. if so, you are expected to graduate your school in June (July?) 2023.
once you graduate the school, you are no more a student. you are not eligible for programs of student exchange.
when you enter university in your country, you are eligible for programs of student exchange in university.

about age restriction:
in Japan, almost all students start school education in the same age and go up to the next grade with no delaying at least up to senior high school. some diffusion may occur at the step of university, but still more than a half of students enter university in the same age.
they expect that students in both sides will gain benefits by exchange programs. probably, Japanese side will expect you are in the same age.

Sorry I don't think I explained properly. I am currently in grade 11, the exchange program I am going into does the long-term Japan trip in 2024 when I am in grade 12. I am turning 17 in June in 2024, and according to google it says that in Japanese schools, 16-17 is grade 11. So will I have to move back a grade??

in general, the final grade in senior high school is busy and sensitive time in Japan, because students need to decide their futures. I am not surprised that school may not accept foreign exchange students in the final grade. follow their application requests. if they say No because of your age, there is no way to do. it just means miss-matching, because it is a trip for you, whereas it is real life for them.
school life is very competitive. when I was young, the school trip was held in the final (3rd) grade, but now recently it is held in the 2nd grade. they don't want to introduce any unessential programs in the 3rd grade.

The ages for grades or year levels is the same in both Japan and Australia. the only difference the the school years start at different time of the year. Oz is Jan/Feb depending on state. April for Japan.

I very much doubt you have been given the correct info regards being an exchange student. Most school dont offerit for students in the HSPT graded aka final 2 years, 11 and 12.

You can whoever possibly be an exchange student and just return to Australia the following and complete grade 12.

I'm an Australian teacher who has taught at an international school in Japan.

In general - schools don't have yearly exchange programs for the last year of school. That's because this is when students study for university exams.

That's why you don't see many students here for a short exchange visit in Australian schools in Grade(Year) 11/12.

Also - if you can't ask the same question you have asked on this forum on a Japanese forum then you will be a potential hinderance to the students and some will resent you for this if it's in their last two years of schooling.

That's why some people have made reasonably strong views in their comments above. It would be like a student in Australia in your Literature class who spoke 200 words of English in Year 12.

If you have decent written Japanese skills - then searching for an education forum in Japanese and asking the question there will most likely give you a much more specific answer than what most of us would be able to say here.

Also from an international school perspective - most of these schools in Japan tend to follow IB/A-Levels which occurs over 2 years. As such - you'd be expected to start from Year 11 as you would not have started the work requirements needed to pass and get a score for university entrance.