No, this has got nothing to do with your rank. However, Selective school, as the name implies, is a school with students with higher academic ability. The select these students from a test in year 6.
Non-selective on the other hand is the average students' school.
If you rank high in a selective school, it means that you are beating top students in your year. iF on the other hand you rank high in a non-selective school, this does not guarantee that you will receive good marks in the HSC (of course, this depends on the quality of the students in a non-selective school)