Just give d manganemental exam like cat,mat etc. N get admitted into a good b school.

In case you are interested in sales management then what can you do is first focus on your graduation and aim at scoring maximum percentage because in MBA many colleges prefer past academic records like in class 10th, 12th and even graduation.
Even after your 12th you can apply for integrated BBA+MBA courses like in IPM-IIM Indore college.

So accordingly you can plan. this year only applications for DU for BBA is only going and in rest of the colleges forms must be over.
If you had maths in 12th, then you can apply.

All the best.