In Christ University Bangalore anyone can apply for any of the BA courses even if he or she is from science or commerce stream. there are only certain courses that expect you to have studied certain subject in 11th and 12th for example economics honours requires you to have studied maths in 11th and 12th otherwise all other BA courses are available to all 12th pass students.
in Christ University Bangalore there is a minimum percentage requirement for all subjects. eligibility criteria can be easily checked on from Christ website. the average minimum percentage required there is 55% marks in your 12th standard ( the aggregate score)
apart from this Christ University always conduct entrance test for all the courses it offers and an interview followed by that.
the basic structure of the entrance exam is English,logical reasoning, general awareness and current affairs and the section focused on the course you are taking up in your graduation.