Colleges in Siliguri

Yes, you are eligible for admission into BCA. Every university has different criteria for providing admission into BCA, so you can try different universities and colleges and check their eligibility criteria for admission into BCA. You can get admission, but you'll have to find that particular university which will provide you admission. If you want to learn programming languages which you will be studying in your BCA course then you can check out this app which is specially designed and developed for BCA students. It has programs and assignments of languages like C, C+ and Java with their outputs. You'll be studying these languages in your 3 years of BCA.
https://play.google.com/store/apps/details?id=technark.bca_courprogramming

To be eligible for BITM, you need to study mathematics in your +2 in order to get admission into BCA. But there are various other colleges from which you can pursue your BCA. As you have studied Computer in your +2, then you can get admission into almost every other college very easily. If you want to learn programming languages which you will be studying in your BCA course then you can check out this app which is specially designed and developed for BCA students. It has programs and assignments of languages like C, C+ and Java with their outputs. You'll be studying these languages in your 3 years of BCA.
https://play.google.com/store/apps/details?id=technark.bca_courprogramming