i need sone tips to prepare for higher exams. like, we should prioritise theories or numericals? for example, i m currently preparing mole concept

Hii I can help you with some books if you need that. Study from these books and topics will easy to you.

Reference Books for Engineering Entrance Exam

Chemistry
NCERT Chemistry text books of class XI and class XII (usually sufficient)
Organic Chemistry by Morrison and Boyd (only for understanding concepts)
Arihant Organic Chemistry Objective (Optional)
Organic, Physical and Inorganic Chemistry books by OP Tandon
Physical Chemistry by RC MukherjeeMathematics
NCERT class XI and class XII books (all students should start with these early)
For best concepts you can purchase ‘IIT Mathematics’ by ML Khanna
New Pattern IITJEE Mathematics of Arihant Publications by Dr SK Goyal
Books by SL Loney (Good for coordinate Geometry and Trigonometry)
RD Sharma
GN Bernnam – only use it for calculus as other sections are too advanced for JEEPhysics
NCERT Physics for Class XI and XII (good introduction)
Concepts of Physics, Vol.-I & II, by HC Verma
Physics by D.C. Pandey, Arihant Publications
Fundamentals of Physics, by Halliday, Resnik and Walker (Optional)