http://www.collegedata.com/cs/data/college/college_pg02_tmpl.jhtml?schoolId=788 shows that rank is very important and GPA is not considered by UT Austin. Therefore, your rank of top 43% makes UT Austin an extreme reach. Basically, the automatic admission applicants (top 7% Texas residents) take up about 3/4 of the spots, so everyone else (all non-Texas residents and Texas residents outside the top 7%) is left with the remaining 1/4 of the spots.