First off please edit your post and remove your phone no. as it is against forum rules to post private info on posts.
Now coming to the point, It really doesnt matter what you choose, what matters is how well you perform in that course and your overall profile should be good i.e. extracurrics, social work and stuff like that. Now since you have done subjects like eco and commerce in 10+2 I really feel you should do your grad in a related stream like B.Com. If you chose to do CA/CS side by side it is purely your choice but like I said
How well you score in your grad is the most important thing. Cos AFAIK there are two groups of people who take CAT. One is engineers and the other group is non engineers

so no matter what you take you are still gonna be in the non engg group which leads me to the final conclusion that you are better off doing a B.Com than a BSc
Now comes the reality check. You are gonna be writing CAT after 3 years and assuming that there are bout 2.25 Lakh aspirants at that point of time, it is gonna be very tough. So prep hard, build a good profile, score well in your grad and Of course the most important step crack CAT

ATB
P.S.: You may get many different views from people far more qualified than me

so I would suggest you to wait for the learned ones to speak and yeah standard disclaimers apply

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