CBSE 12th

There is no chance that you can write examination of class 10th without mathematics as mathematics is compulsory subject in class 10th. Yes, you can opt commerce only. Some part of economics also compulsory in class 10th. You have option to select your desired subjects. So, you can have commerce art or science as option of studies. For BBA qualification is class 12th pass in any branch commerce science or art. Yes, you can study BBA.
But, these subjects are core subjects for BBA, you have to study accounts and management subjects in entire syllabus. Mathematics is compulsory in first semester of BBA second and third semester, you have to study statistics, statistics is part of mathematics. Yes, your IQ will increase when you will be students of BBA. You have good will power so sure you will clear all these subjects without any problem.

Please be very careful while choosing your branch and take care of the below points:
1. Don't take a branch that is a derivative of some other beach, like Industrial engineering, Instrumentation, Biotech, Automobile or Aeronautical. Most of the Indian companies are service-based, so none of them look for such skill set.
2. Choose from Mechanical, Civil, Electronics, CS IS but not electrical and chemical, again you won't find jobs, in electrical and the subjects taught are tough too.
3. Go through the curriculum of all the above-mentioned branch, relate them to the subjects you studied in class 11th and class 12th. Try to figure out what all you don't want to study, you will automatically realize what you want to study. I think that's what you wanted to know. Hope I have answered your question.