Hello aspirant,

Hope you are doing absolutely great.

So with regard to your query, YES it is better for you to go to the coaching for any of these exams like NDA and IIT. Even though you have courage to prepare on your own, sometimes at least short-term coaching for the exams might be helpful for you. Because due to more number of people giving these exams, the standard of the exam is heightened every year. So, just take some kind of coaching for the exam, and then prepare on your own, you will score good marks definitely.

You can also checkout the previous year papers of JEE Mains to know the difficulty level of the exam: https://engineering.careers360.com/download/jee-main-sample-papers-previous-years

Hope this helps you,

Good luck, Thank you.