B.A

Hi,
Delhi University conducts DU LLB Entrance Exam in order to shortlist aspirants for admission in LLB programmes offered by it. The syllabus for DU LLB Entrance Exam is:
1) English Language and Comprehension
2) General Knowledge and Current Affairs
3) Reasoning and Analytical Abilities
4) Arithmetic
5) Legal Awareness and Aptitude
For English you can refer - RS Aggarwal, Word power made easy (by Norman Lewis) and practice RCs from previous papers
For arithmetic you can refer - RS Aggarwal and M. Tyra.
For Reasoning you can refer RS Aggarwal or any other reasoning book will do. For static GK - Lucent and for current read newspaper and any monthly magazine give more emphasis on legal current affairs.
For Legal GK and reasoning you can refer Andhra Pradesh Bhardwaj.

Hi,
Yes, you can go for B.A. LL.B after your 12th with bio sciences. The eligibility for B.A. + LL.B. Hons. In most of the top universities is pass with 60% aggregate marks in 10+2 and you might have to clear some entrance test of the university (depending upon the university you want to take admission in).
It will be advisable if you do your degree from a well-known university and that provides prime placement opportunity, outstanding exposure and professional enhancement training. I can enlist some universities for your help-
Lovely Professional University, Auro University-Surat
Banasthali Vidhyapeeth-Jaipur
GLS Law College-Ahmedabad
Institute of Law, Kurukshetra University – Kurukshetra
These universities provide extensive learning programs and exposure to the students. They also provide worthy scholarships to its students depending upon the entrance test taken of the university or board result.

Yes, you can do MA after completing BA. You only need Bachelor's degree in arts stream for taking admission in MA Sanskrit.
Academic options:
Upon successful completion of the course, postgraduates interested in further studies in the discipline may go for pursuing MA in Sanskrit literature, B.Ed or PhD in Sanskrit or Masters in mass communication and journalism with specialisation in Sanskrit Patrakarita.Other options include pursuing Postgraduate Diploma in Functional Sanskrit and Translation, or Post-Graduate Diploma in Sanskrit Journalism. Rashtriya Sanskrit Sansthan also offers such postgraduates the option of taking vocational training in Sanskrit short-hand and typing and cataloguing manuscripts.