To do MBA you have to be a graduate at least with any stream. After 12th you can either apply for BBA/BBM (related to management) or you can choose to integrated management program for 5 years like BBA+ MBA.

IIM Indore provides such a course. The notification to apply comes in the month of March each year.

Also when you are in your second or final year of graduation, start preparing for MBA exams like CAT, MAT, XAT, CMAT etc to get into top management institutes in case you don't go for integrated program of management after 12th class.

Some of the govt colleges for MBA in Delhi are:

GGSIPU

FMS Delhi

Jamia

IIFT

Hope this helps.

Good Luck!