It is unexplainable to use Backlog marks for the calculation of Aggregate. 

The marks before backlog do not count. You have cleared them so Your new marks will be counted for this purpose. Backlogs marks will be never used anywhere, everywhere Your marks after clearing Backlog will be entertained.

Hello Prasoon thanks for asking this question on this platform.if you got a backlog in any subject then you get a chance to clear it by giving exam then the number you got in that subject that will be calculated as your marks in that subject .and then aggregate will be calculated by taking marks of all subjects .thanks