Hi student

You have not mentioned the question properly.It would have been great if you would have mentioned the board which you belong to.

Every board has their own criteria and they calculate marks accordingly .

You can also  consult regarding this to your school authority .

Hello,

Index calculation is done on the basis of some term  like score-wise,percentage wise, subject-wise, college wise, state wise.... etc.

Your college will do it and publish notice. You can ask your college authority for index list for your batch. if they have made then they will send you or publish it in their official webpage.

if you are asking about index marks calculation then the formula is 2*maths score + physics score + english score.

Hope it helps!