I’ve been to two high schools for 9-10th and then 11-12th. I was in the top 5 people of a 300~ class in 9-10th grade, but my current high school doesn’t rank at all. Am I allowed to use a previous ranking, or is it considered invalid because it is not my graduating class?
No. It’s like asking if you could use your 10th grade ranking if you attended the same HS for 4 years. The answer to both questions is “No.”
Use the ranking from your current school, which in your case is “None.”
^^^^Agree.