Hello 

For doing BBA, you should have opted for commerce with maths. That will give you extra advantage in BBA. Being a science stream candidate, you may face some problem while persuing BBA. 

But, there a a lot of students who persue BBA after completing 12th from science stream, so you can also do that but students from commerce stream generally have additional advantage in the course. 

I hope this will help you. All the best.