B.A

No, sorry you can't get in Xaviers with that score for any course.

For getting admission in Institute of Distance & Open Learning (IDOL), one needs to fulfil the eligibility criteria. There is different criteria for different streams. So, the criteria of BA Says:
*You should have passed HSC (Class 12th) or Equivalent Exam
*You should have passed for admission to FYBA (First year B.A. Course.

The questions that can be asked in BA entrance exam can be multiple choice question, objective question or descriptive questions and mostly, questions will be asked related to your general knowledge, general awareness, and your class 10th, class 12th NCERT books.
I would suggest you to read newspapers, magazines. So that you can get more information about your surroundings. And also read your NCERT books as much as you can. As maximum entrance exam questions are put up from NCERT books

I wouldn't recommend. However, this depends on what field of Economics you are interested in and what combination you are planning to take during your first year.

Yes, you can do registration for both BA and B.Sc course simultaneously in Chaudhary Charan Singh University in Meerut. So that, if you don't get admission in one then you are able to apply for another one. Here is the registration page link: - https://admission.ccsuweb.in/

There is no such criteria in St. Xavier's College for the admission in Undergraduate programmes, as for you, BA in economics. The only eligibility criteria for admission in any undergraduate programme in Xavier's is a passing certificate of 10+2 from any recognized board such as CBSE, ICSE or any state board.

Yes, you can apply for any college you like in Mumbai, you just need to apply by filling the application form and meet the eligibility criteria.

No, according to the college's eligibility criteria, one language and three electives of LIST A are combined to calculate the merit for the admission and physical education is not included in LIST A. Following are the subjects included in LIST A:
Arabic
French
Legal Studies
Punjabi
Bengali
Geography
Mathematics
Sanskrit
Botany
Geology
Music
Sociology
Chemistry
German
Persian
Spanish
Commerce*
Hindi
Philosophy
Statistics
Computer Science
History
Physics
Urdu
Economics
Home Science
Political Science
Zoology
English
Italian
Psychology.

Yes, you are eligible to apply for Jamia Milia Islamia. In Jamia Milia Islamia, admissions are done through entrance test and for applying for the entrance test, the minimum percentage required is 50%.

The admission procedure starts as soon as the results are out, so once you get your 12th board results, you have to fill an online application form and then you need to check the colleges that provide B.A. in Mass Communication. The cut-off for the course will be available on the official website of the college. Also many colleges conduct an entrance exam for the same, so please keep checking the official website of the colleges.