There is a Supreme Court 2016 judgement which clearly mandates that admission to any professional course in India must be strictly based on a common entrance test and not on XII Boards marks. The XII Boards marks shall thus have zero weightage and merely serve as an eligibility criterion for admission to all colleges. For example, the IITs, NITs, IIITs expect a student to score 75% Aggregate marks or be in Top 20 Percentile in your respective Board in XII Boards to be eligible to join the colleges. Similarly, BITS PILANI expects a student to score 75% marks in PCM subjects to be eligible to join BITS whereas Maharashtra Engineering colleges expect 45% marks in PM + C subjects to be eligible. Admission is always granted on the basis of Entrance exam ranks but they crosscheck if XII Boards eligibility criteria is cleared or not.