Science

MCA with specialization in big data analytics course is sort of equivalent to M.Sc data science
Look at both words "Data Science" and "Big Data", what is common? "Data". Both Data Science and Big Data are related to Data-Driven Decision but are significant.
Data-Driven Decision (with the expectations of the better decision and increase value) processes and involves different stages
Capture Data
Process & Store Data
Analyse and Generate Insights
Decision & Actions
Big Data is typically involved in Step 2 and that too in all the scenarios. Based on volume, variety and velocity, one may require Big data & related technologies. Big Data & Technology helps in reducing cost in the processing volume of data and also making it feasible to do a few typically analyses.
Data Science is involved in Step 3.
It involves in using Statistical, Mathematical and Machine Learning algorithms to use data and generate insights. Whether a data is "Big data" or not, we can use Data Science to support Data Driven Decisions and take better decisions.

It depends on your interest and the field in which you want to pursue your career. There a number of areas in the science field. The courses mentioned in this list are non saturated or less saturated. It means that relatively less number of students opts for these courses. This means that competition in the job market is remarkably less. It also means that the demand and supply gap of qualified professionals is not filled up. As a result, graduates having completed these courses will get good jobs relatively easily. Another trait of this list is that you won't find already famous and much chosen B.Sc. courses. For example, I am not mentioning common B.Sc courses like Computer Science, B.Sc Nursing, etc. Sure, they do have excellent job scope and all, upon pursuing from good colleges. But then everyone is aware of those courses. I am about to mention less known ones.