Science

Mathematics is compulsory for all entrance examination of MBA colleges in India and also abroad. Hence I don't think you will be able to skip mathematics. However it is basic maths not the advanced version (means: calculus, 3D etc are not included). There are a lot of non-science background students who has joined IIMs in the past. I don't think there will be any problem for you in that regard. You just need to practice a little bit.

what is ur expecting marks in 12?

BTech IT is a four year enginerring course. In addition to IT subjects you will be exposed to basics of engineering via subjects which are common to all branches of engineering. BSc IT is generally a three degree course. It is not as rigorous as BTech. 80% of IT syllabus of both degrees is same except for rigor and content. BSc IT can be at best equated equal to BCA. MSc IT is treated equal to BTech IT. With BSc IT you may get lower salary jobs as Indian IT companies prefer BTech CSE or IT students. With BSc IT your chances of getting onsite assignment are almost nil.