Dear Saikat! 

An aspirant should have passed 10+2 with minimum 45% in aggregate.The Council for the Indian School CE Examinations (CISCE-ICSE/ISC) is a non-governmental , private board for school education in India. The syllabus is vast giving due importance to all the subjects.Considering that the maximum rate of the passing percentage in ISC is quite high, getting above 45% for a student is quite easy

All the maximum law institutions in India have 45% or 50% as the eligibility criteria.

Hope this helps you!

Good luck!