University of Texas Dallas

I know my scores and ranking are pretty low but I just wanted to see my chances of getting in

SAT old one (#1): 550 CR, 630 Math, 570 Writing, Total 1750
SAT old one (#2): 510 CR, 660 Math, 620 Writing, Total 1790
SAT new one: 1180

High School GPA: 3.3/4.0
Rank: 145/593 (26%)

I am planning to retake the SAT or take ACT

The good news is UTD super scores and only considers the highest CR and Math so for your old SAT = 1210 so you should be in based on your super scored old SAT.

So does that guarantee getting accepted into my major (Business) or just the school itself?

Just the school.