Hello,
Yes, scoring around 80 percent in PCB boards with 15 days left is possible if you study smartly. Focus mainly on NCERT textbooks, especially Biology, and clearly understand all concepts, diagrams, and definitions. Solve textbook back questions, in-text questions, and previous year questions. Avoid multiple resources, revise daily, and use the last few days only for revision. With disciplined and focused preparation, 80 percent is achievable.
For more preparation tips, Kindly check the below link.
https://www.careers360.com/webstories/preparing-for-board-exams-in-30-days/
I hope this helps you.