CBSE 12th

To do MBA, you must have 50% marks in graduation (any stream). Apart from this, you need to clear any national level entrance exam such as CAT/ MAT/ XAT/ LPUNEST/ NMAT/ CMAT/ GMAT. After qualifying written exam you have to go through GD or PI. Many colleges offer this course in India with different specializations. You can choose any specialization as per your interest. Even you can go for dual specialization. I am mentioning a few of them:
Specializations:
Oil and Gas Management
Hospital and Healthcare Management,
Supply Chain and Logistics,
Tourism and Hospitality,
Financial Markets,
Finance,
Marketing,
Human Resources,
Business, Operations,
Information Technology,
Retail Management,
Strategy,

Since you are still in school, in case you are focused on doing law, the best option for you would be to sit for CLAT and aim for an NLU. NLUs in India are the premier institutions for studying law, both in terms of legal education and in terms of opportunities available to students who study from NLU's. The top ranking NLUs have been known to churn out the best in the field year after year. The CLAT exam for entrance to NLU's is an annual exam conducted in May every year. The questions are MCQ pattern with negative marking for every wrong answer. The exam is of moderate difficulty and it is essential you prepare well for the exam as Lacs of students are fighting for a meagre thousands of seats, that too for the best colleges in the country. Apart from NLUs, there are several other good colleges for doing law. However, there are separate entrance exams conducted for those. A good idea would be to first make a list of colleges that you are targeting and, accordingly, make a list of the entrances that you will have to give.