Dear aspirant

There is no fixed chapters from which conceptual or theoretical questions can be asked it may be asked from anywhere. Although I'm giving some chapters name from which theoretical questions can come. In physics semiconductor, modern physics, light and dual nature, fluid mechanics etc this are the main chapters from which theoretical or conceptual or formula based questions may arise in physics although it's not fixed.

In chemistry chapters like solid state, biomolecules, polyester, chemistry in every day life, environment chemistry,periodic table, hydrogen, surface chemistry, principal and process of isolation of elements etc so these chapters can give you theortical questions.

Almost every chapter mentioned above will give you one question from some you might get two also.

You can also check the link below which will tell you the chapters which you must read to score high

https://www.google.com/amp/s/medicine.careers360.com/articles/do-or-die-chapters-for-neet/amp

Hope this information helps you

All the best !!