Both the exams have already happened and their results are also out, so, i believe you are asking for next year. Even if you don't give improvement you are still eligible for both the papers. As a person who is currently pursuing B.tech, I would recommend you to start working for these entrance exams instead of wasting your year for improvement as they would help your overall development of the subjects. But, if you are going for chemical engineering or any other engineering where chemistry is the core then you should definitely opt for improvement.

i hope this advice would clear your doubts. 

Hello Arnav,

If you are going to give improvement exam than the marks after giving improvement exam will be considered so which means it says you are still in class 12 only by the way if you want to carry your higher education with this percentage only than you can apply for jee and other exams.

I hope my answer have helped you and hope you do well in future.