Hi,
For admission in MBA first you have to complete your graduation. graduation is must for MBA admission. after graduation you can apply for MBA entrance exam.

For graduation you can take admission in college or can take admission in degree program like BBA,BCA and other equivalent program.

For admission in MBA you have to apply for entrance exam. CAT,CMAT exams are conducted for admission in MBA program. some universities take direct admission without any entrance exam and some universities conducts its own entrance exam for admission.

CAT is best exam for admission in MBA program. CAT exam is conducted every year for admission in management courses. CAT exam is conducted for admission in IIMs colleges. IIMs colleges are best management colleges in India for MBA for admission in IIMs you have to score 96-99 percentile in the CAT exam after clearing written exam you will call Group discussion and interview if you clear these then you can get admission in MBA program.

Hope this helps!