CBSE 12th

The cut-off of this year of Mains exam for OBC candidate around 63-65, so you need to score 65 marks to qualify for advance examination.
Regards.

You can go for economics Hons or B.Com (Hons).

It's difficult for you to take admission in DU with this percentile as the cut-offs are very high but you can still try when the cut off comes.

I am from ISC board but as far as I know, you can score good marks if you study NCERT.

Hi, I suggest you to take up BBA. You have many specialization to specialize in MBA. This is one course suggested for students. B.Tech is difficult when compared to BBA. The growth in BBA and MBA is equally significant. Few specialization, which help you in the long run is Sales and Marketing, HR, Finance, Banking, International Trade and many more. This will help you to decide which the right one during your BBA studies is. As this has wide options to sustain, I suggest you this course in the present scenario. All the best.

Yes, you can get admission in MCA without Math in class 12th, because you have completed BCA, so don't worry you can apply.

Amity University, Gurgaon
PDM University, Bahadurgarh
Manav Rachna University, Faridabad etc.

I don't think so. You can pursue B.Sc, in any of it's branches, only if you belong to Science background.

That is not entirely true. You need a decent score in your HSC. But, there are colleges which give more value to the entrance or JEE than your HSC score.