Hi monofseniro1 - what UT Austin policy is - if the 6% is less than 1 student - then they will take the Top Student as the Auto Admit Student.
So if you go to a top school, magnet/public/charter - say with 50 students in the graduating class - you have to be in the Top 3 to be admitted in Auto Admit and if you apply to some of the top programs as UT BHP, Plan II Honors etc. - you have to be Top 2% - meaning your chances are Much Greater going to a public school with 600 students and and if you are one of the top 12 students in the graduating class, you can most likely get in to one of these programs.
Top 6% penalizes Top Schools (Magnet/Charter) which tend to have smaller classes - I wish they will compare common tests that these kids take to compare them - such as AP or IB classes, SAT, ACT, SAT Subject Tests. Many of these schools, top 30% is better or equal to top 1-2% of a regular high school.
In many countries around the world, they have final testing in the final year common test with the grading done by unknown people (only a number of the student is provided - no names) and also, an entrance exam that is extremely difficult is also part of the admission system.
Top 6% from every school is NOT a merit based system - about time we give Merit its due place in admissions! OR, at least have additional grading that are common say SAT subjects etc. to compare students.