Is it possible to score 90 percentile in JEE in 39 days? Please help me.

I’m a Class 12 student preparing for boards. I didn’t join any coaching for JEE because I was planning to take a drop year and study properly after that. But now, my dad is completely against it. No matter what I say, he won’t agree. So, I made a deal—if I score at least 90 percentile in JEE, he will allow me to drop. But the truth is, I wasted Classes 11 and 12 thinking I’d cover everything later. And now, I have only 39 days left. I feel stuck. I don’t want to end up in a private college, and I don’t want to give up on my dream. But I have no idea how to pull this off in such a short time. Please, if anyone has any advice—how to study, what topics to focus on, how to maximize my score—help me out. I’m willing to do whatever it takes. I just need a plan that works. I can’t afford to fail this. Please, any guidance would mean the world to me. 🙏