Maths Spl

If you wish to remain in the business subject, then there are no undergraduate degrees or Diplomas for 2 years. you will have to pursue them for at least 3-4 years at Bachelors level. If you wish yo can look at hospitality/hotel management Diplomas. Although degrees will be a better option than Diplomas at this stage.

Arts is a better choice but you may go for commerce though little pure maths is there.

go for B.Sc CS or it as in B.Tech math is in 3 sems but in B.Sc math is easy then B.Tech

Students from any stream can apply for BBA course. Best BBA institutes are Christ university, UPES Dehradun, UTM Shillong, Symbiosis, Mount Carmel College Banglore & Madras Christian College Chennai. You can choose as per your location preference. Eligibility & admission criteria you can get on the website of these institutes. Good luck!

If you are interested in engineering go for it as you are good in mathematics. You may go any stream of your choice either biology or mathematics or arts or commerce, but don't go against your interest.

Dear Steffi, if you check the websites of each of the universities carefully you will know that GRE is not mandatory for students having a prior degree in mathematics. Having said that since requirements and selectivity depends on a particular university alone I will strongly advise you to communicate with the universities directly.
Best Wishes