Institute of Distance and Open Learning University of Mumbai Santacruz East Answered Questions

The admission to the course is based on either entrance exam or marks of last qualifying examination. MCA course is a study that provides an in depth and extensive knowledge about computer applications. The course includes study related to computer languages, application of computer science in IT field, Data Structures, Mathematics involved in computer science, and alike. MCA syllabus is formulated to enable candidates to have a stable and prospering career in IT industry. There are not many eligibility criteria that needs to be fulfilled by a MCA aspirant for securing admission to the course. He/ she needs to have passed bachelor degree course in computer applications (BCA) or any related fields. In case of merit based admission process, the candidate need to have secured minimum aggregate marks as per the institutes requirement in last qualifying examination. In case of entrance exam, the candidate is must to clear the entrance exam and subsequent rounds such as GD and PI to secure admission in MCA course.

commerce student can’t apply for B.Sc IT. B.Sc IT: Eligibility Candidates wishing to apply for B.Sc IT course need to have completed the 10+2 level of education from a recognized educational Board, with Physics, Chemistry, and Mathematics as the main subjects, and with a minimum aggregate score of 50%.

In case you intend to change your university and course mode after completing your 1st year, I don't think it is possible. In certain cases, college change within the same university is possible to a large extent but not the mode in which the course is pursued.
You can still check with your college authorities.