Bhanu one very important thing I want to tell you that is no matter which course you do, which branch you chose you to need to improve your communication skills. 

Communication skill is an obvious requirement for your growth irrespective of your field and branch. You have ample of time before you start working it's better you improve your communication skills otherwise it will hamper your growth.

Now if you talk about the course as you are good in calculations and seems interested in Maths field so I will recommend you to take BBA in Finance and Accountancy or BBA in Finance and International Business course. Both of them are very good course and creates ample of opportunities for you in the future.

Feel free to ask if you have any more queries. All the best!!