For IIT JAM physics having clear concepts and strong basics are always important. Remember selection of books are very important. Now you can read books which you have read in your semester exams but be relevant with the syllabus of IIT JAM. Also do practice previous year papers in order to test your skills in problems and to get accustomed with pattern of the paper.

Some of the books which are said to be the classic books for IIT JAM/JEST/TIFR are :

• Mechanics: 'David Morin','AB GUPTA' JC UPADHYAY, GOLDSTEIN
• Waves: 'NK BAJAJ'
• Quantum Physics (all the books are relevant to all the exams): Griffiths, Beiser, Resnick-Eisberg, Zetilli, Arhuldas(problem solving)
• Atomic Physics: Rajkumar
• Mathematical Methods: ML BOAS, HK DASS
• Electronics: VK MEHETA (Both Digital and Analog)
• Statistical Physics & Thermodynamics: BANSAL & GHOSH, Zemansky
• Electrodynamics: Purcell, Griffiths
• For problem solving you may use the books by Samvedna Publishers

To know more about IIT JAM  visit the link below:

https://university.careers360.com/articles/jam

I hope this answer helps. All the very best for your future endeavors!