Accounting

Your percentile is really low, but still you can get information about ranks and colleges from this link. Hope you will get what you're looking for.
https://www.shiksha.com/college-predictor

Yes, you can now register for CS, and there are 8 subjects in executive stage.

Hi,
Yes, you can straight away register for CMA Inter after your graduation. Just check out the website of institute to know the process and to register. CMA consists of three levels -
Foundation, Intermediate & Finals
Once you are graduate with any discipline except fine arts, you are directly eligible for CMA Intermediate. You are exempted for foundation I. e. no need to appear for foundation exam. All the best.

Hi,
Of course you can study M.Sc in computer Science. A lot many students do pursue this course. You have to give TOEFL/IELTS exam and prepare a very good cv/resume for the top universities like Oxford, Cambridge, Princeton etc. Other universities may take admission thorough an entrance exam. Here is a link that will help you:
https://studyabroad.shiksha.com

Yes, Alliance University is a good university for B.Tech in computer science and engineering. there you will be getting a lot of opportunities, exposure and knowledge. The one thing that you have to maintain is your score.

Use this tool to list all colleges you can get. https://www.shiksha.com/college-predictor.

Please use the college predictor tool by Shiksha. This will help you to predict the college according to your rank/percentile:
https://www.shiksha.com/college-predictor

Yes, according to me, you should go for IIIT and not for IIT as CS has more scope than mechanical and the college doesn't matter in comparison to branch, what will be the benefit if you get a job in mechanical and not get promotion due to its very less scope.

Yes, possibly you will be able to get B.Sc (Hons) in CS.

Yes, you can take admission. You have to clear the entrance test then the university will allot you a college.