B.Com

Yes there are colleges which offers admission to candidates with less than 50% marks like Symbiosis. There are many more in India. Only criteria one has to fulfil that one should have good score in CAT or MAT. Just prepare of these exams and score well. Also you can go for distance learning and in this there is no criteria as such to pursue MBA.

MBA would be a good option.

Nah! Not to worry about that. You just need 50% on your degree at last.

All the courses has greater importance in their own field it depends on your interest which course you want to select.

B.com is blend if theory and mathematical. According to Mumbai University syllabus there is maths subject in first year then after that there are some theory subjects and some practical subjects like accounts, tax, costing and theory subject like economics, advertising, export marketing and many more

Go for what interests you. If you wanna go into IT sector, take up BCA. If you're interested in banking sector, take up BCom. Decide well !!

if you want bright future you will do CA, CS, CMA OR BBA MBA with good college

Here, this will help you surely.
http://www.gim.ac.in/2015/how-to-apply.php#eligibility