Hello Arnav,
The first mark sheet you'll get during your actual boards time and if you'll give improvement exam you'll be given one separate mark sheet with the improved marks.
You don't need to worry because both mark sheet will be valid and improvement mark sheet is accepted in every competitive exam like selection in Jee, BITSAT and even in IIM.
Just show the mark sheet whichever have better marks during the admission. That's it.
Good luck!
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile