Bit of background for non Texas residents: there’s a law in Texas stating that if you’re in the top 6% of your graduating class (for applicants for fall 2019) then you get automatically admitted into UT. The law also requires that 75% if admits are part of this group but it only guarantees liberal arts majors and not engineering , business , etc.
My school is extremely competitive having 77 National merit semi finalists last year (and probably even more when my class’s scores come out). My current GPA is around a 4.402 and my SAT is a 1540 and 34 ACT and i picked up my transcript today and found out i wasn’t top 6% (was around 3 people out of it 
). Do i still have a decent chance to get into McCombs business school at UT even if I’m not top 6%?
For UT admissions the most important thing is the class rank. They don’t care about your GPA. So with a top ~7% class rank and an excellent 1540 SAT, you should have a far higher chance than anyone else outside of the auto-admit group of top 6%.
I think you have a very good shot. Even though you were only a little edged out of that automatic spot, your standardized test scores are well above average, and you’re ranked pretty highly. I have friends ranked 8-10% who have gained entry into McCombs, and their scores weren’t incredible, but they were Texas residents.
I will say, be sure to apply early enough, since nothing is guaranteed.