I want to strengthen my organic theory for JEE mains. Should I study theory for organic from Pradeep Objective Chemistry?

Dear Aspirant,
In my opinion you should not use Pradeep Organic Chemistry book as it is very big book and won't help you in preparing for JEE. There are many books available in the market. As of my experience these are some books which you can go through and get prepared -

1. Of course the best recommendation is NCERT Part - I & II.
2. H.C VERMA as in this book they explained organic chemistry very perfectly.
3. You can also go for P. Bahadur book.
4. Arihant series is also a good choice for question solving.

So this is my opinion for your question.
Hope This Helps.