UT Austin admits about 3/4 of its frosh from Texas residents in the top 7% (or 6% in the near future). Based on application and admission numbers, the non-auto-admit applicants have admission rates of around 15%. Note that class rank is used instead of HS GPA.
Both UT Austin and UIUC fill up their engineering majors with direct admit frosh, so changing to a different engineering major after enrolling can be difficult. So can changing into one if admitted to the school but not the major (engineering majors have an additional selection hurdle beyond admission to the school).