BCA

I would suggest AIT and MS Ramaiah as well for a technical course like BCA.

You can go with AIT because AIT is more in technical education. and you can consider ABBS too.

My recommendation is do BCA and then MBA. Don't go for BBA. If you study BCA and MBA, probability is high that you will getting managerial jobs in IT companies in final placements of MBA. These jobs are also well paid.

This would depend a lot on your interest areas & career aspirations. However, since you have done 12th in arts you should pursue BBA. BCA (Bachelor of Computer Application) is a technical course and one would need good computer skills plus an HSC in science would be necessary to seek admission.
BCA can also be Bachelor of Commercial Arts, if you are creative in nature and have good drawing skills then you can pursue commercial arts course as well.

55% is the minimum percentage that you need in clas 12th.

No, MS-CIT is just a computer course. MCA does not require any such course for admission.

You are eligible to seek admission in MBA. Although, regular MBA is best for your career, you can do MBA through distance learning while on job. You may choose any MBA regular or MBA distance learning based on your personal conditions or constraints.