Hello aspirant,

I hope that you are doing absolutely great.

With reference to yoru above mentioned query, i would like to tell you that your class 12th Boards will compulsorily be there. So, there's a choice between JEE mains or NATA that you should be more focused upon. If you wish to give and prepare for JEE mains and boards simultaneously, then it's fine you can do that. Many candidates do that every year. And if you wish to give and prepare for NATA and Boards simultaneously, then there's a not problem on that Too. The thing is that you should pickup one thing - JEE mans or NATA, then you should start preparing for it.

Further, I wpould like to give some expert level tips and preparation strategies that you can follow to prepare for JEE mains( or NATA) along with Boards exam simultaneously :

1. Smart Planning is Important to study well in both boards and competitive exam,

2. have a clear and basic level of understanding of all concepts in All competitive exams and boards

3. Cover every topic of the syllabus

4. Revise well regularly for every chapters

5. Get your self accustomed with the latest exam patterns of JE Emains ( or NATA) and Boards

6. Practice Mock papers.

Further, if you wish to know preparation tips and important books for JEE mains and NATA and Boards  and other relevant details then you can follow the below mentioned link to know more : https://engineering.careers360.com/articles/how-prepare-for-jee-main

https://engineering.careers360.com/articles/how-prepare-for-nata

https://school.careers360.com/articles/class-12th-board-exams-preparation-tips

i hope that this will help.