Jawaharlal Nehru University

The date of JNUEE 2019 is 5th May.

Yes, you can apply for M.A. If there is no entrance test for M.A. Only Bachelors degree is required for M.A.
All the best.

Refer the following:
https://www.jnu.ac.in/admission

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 knowledge, you can get admission because the only requirement to just clear the entrance exam irrespective of the marks scored by you in your class 10th and 12th.
All the best.

JNU will release the exam notification when the forms are out. You will then get admission on the basis of your result.

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.

Yes, you can pursue BA in Russian language and for that you need to clear an entrance exam conducted by the college and you must have scored 60% in 12th.

The last date of admission in JUEE for Bachelors degree in Spanish is 13th October, 2018.