Jawaharlal Nehru University Delhi Answered Questions

JNU Eligibility Criteria 2019 for MA in Politics (with specialization in International Studies)
Candidates should have completed their graduation in any discipline under 10+2+3 education pattern with minimum 50 percent marks.
If you clear the above eligibility criteria, then you can fill form which releases in October.

Hello Krishna,
Yes, you will be eligible to pursue MA in International Relations from JNU. You should have obtained at least 50% marks in your graduation. I am attaching a link that will give you all the required information about admission process for MA in JNU.
https://www.jnu.ac.in/node#school_center

Online forms are available and they conduct entrance exam on the basis of that you will get admission. You can have an idea about the questions asked in the entrance by looking at previous year's questions. So, to look at previous years questions is a must for every aspirant. Please study on these topics extensively. Internet is a good place to read and also, you should read The Hindu Newspaper and Frontline Magazine.
Source: -http://jnueeqp.com/how-to-prepare-for-jnu-entrance-exams/

As per my opinion and my knowledge, you cannot go for Science. As per my opinion and my knowledge, you must go through internet, as there you can find previous year question papers and all that will help you much better than any other books. So, go for it. All the best and have a great life ahead.