I think someone else commented on this but I would be cautious going this route. If he wants to study Engineering - find a program where he will be in that program or can easily transfer in. At UT, I believe it is very difficult to transfer majors, especially business and engineering.
FWIW, my daughter had a 32 ACT and was in the top 8%. She was CAP’d at UT 
Perhaps your son will have a different result but UT is a tough one.