Science

For B.Sc. course, the college has an online application system through a facility on its website. This facility is made available from second half of May. An incomplete application will not be considered for admission.
All applications for admissions to any UG course should be submitted by the date notified by the College. Late applications may not be accepted.
The University of Mumbai has made it mandatory for all candidates seeking admission to the First year courses in the Degree Colleges to fill in the Pre Admission Online Registration Form is available on mum.digitaluniversity.ac
Actual admissions to all courses will be on the announced days, through an interview of the candidate and a parent / guardian. The offer of admission will be notified on the website, on the College Notice Board.
The basic eligibility criteria of B.Sc. at St. Xavier's College Mumbai is HSC with minimum 45% of marks and the admission will be based on merit (12th Marks). The minimum cutoff marks of B.Sc. course is very high (about 90%) for admission. Hence you have to score above 92% of marks in your HSC for admission here.
So keep in close touch with the college website regarding the admission updates.
http://xaviers.edu/

You have not write about the name of College/University where you wants to pursue the B.Sc. Hons biochemistry course. However, the eligibility criteria of University of Delhi for asked course is given below for reference only.
Eligibility criteria : Candidates seeking admission to B.Sc. Biochemistry (Hons. ). Should have passed Senior School Certificate Examination (class XII of the Central Board of Secondary Education or an examination recognised as equivalent thereto. A candidate must have obtained 55% or more marks in the aggregate of Chemistry, Biology/Biotechnology, Physics/Mathematics. I. e. PCB or CBM (Practical & Theory together) and Passed in one compulsory language (I. e. English). So from above your marks are enough to apply the B.Sc. Hons biochemistry course. However, the admission is subjected to meeting the Cutoff/ Entrance criteria as applicable.

The CLAT Exam is a test of one's aptitude and reasoning abilities. It comprises of five sections namely: Verbal Ability, Quantitative Aptitude, Logical Reasoning, General Knowledge and Legal Aptitude. Each question carries 1 mark and for every incorrect attempt, 0.25 marks will be deducted. The Mathematics section of the offline national-level law entrance exam will basically have elementary numerical ability questions of Class 10th standard carrying 20 marks. The questions will cover a varied number of topics including Number systems, Algebra, Co-ordinate Geometry, Trigonometry, Mensuration, Statistics and Probability. Recommended books : The following books are recommended for preparation of Quantitative Aptitude section of CLAT exam.
1. Quantitative Aptitude by RS Aggarwal
2. Class 10th NCERT Textbook.