Some courses in the universities require you to take up Math AA HL or AI HL specifically. But then again, it depends on which course you are applying for. In most cases, when you apply for undergraduate degrees like physics or engineering, colleges require you to have taken up Math AA HL. However, other courses that don’t need math as much look at your overall score instead.

All in all, they go hand in hand. So, it is better to make a decision of which mathematics you have to take depending on what your desired college requires for admission.