Hello Kritesh,

Since you didn't study well in 11th and 12th classes you need to be patient and learn the fundamentals of all m,p,c in 3-5 days. Have a plan, know the syllabus, and Always start with chemistry and end with physics, Take breaks frequently, Refer to previous years' question papers, grab more and more knowledge from youtube lectures, and don't waste time, instead explain what you understood, "Early to bed Early to Rise". ALL THE BEST FOR YOUR FUTURE!!

Hope this helps you.