Yes, you should give both paper of Jee advanced 2021. As jee advanced is for selection to IIT colleges, it has nothing to do with your mains exam. If you get selected with higher scores in mains exam, its good for you to give both exams of advanced level. As it will help you to boost your score and you can get good ranks. If you score higher in other attempt, you will get a better college for engineering that will help you with good placements.