Hello,

you have to be eligible for JEE main exam. If your percentage is not making you eligible then you have to give improvement exam and appear for jee main. As your 12th was in 2019, you have more 2 attempts left i.e. this current year 2020 and 2021. After that you won't be eligible to give JEE main  exam. Keep note of it. and try to improve your percentage.

As you said you are not eligible for JEE , other entrance exams also has percentage cutoff as eligibility criteria. You won't be eligible for them too. Do check eligibility criteria of your state entrance exam. If it is making you eligible then do appear it and try to score good and get an admission.

On the part of JEE , if your percentage in not making you eligible then you can't appear the exam so improve your percentage and appear in the comming sessions.

Hope it helps!