Hi Ajay,
The percentages will be calculated the same as calculated for the other board.
To calculate the percentage for 6/5(depending on the subjects you choose) subjects in class 12th, you have to calculate the total marks that you have secured in the examinations to the total marks for which the examination is conducted and multiply the obtained result with 100 to get the percentage.
Hope this information helped you.
all the best
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile