Please be specific about your topic, particularly the topic, you are comfortable with (not the topics from where hardly any questions are asked e.g sound) . Don't need to read every topic for IIT JAM Physics 2019.
By the way, my main textbooks were-
HK Das- Math physics
SN Ghosal- Atomic and Nuclear
DJ Griffith - Electrodynamics and Quantum Mechanics
Gupta, Kumar- Classical Mechanics (you can try Schum's outline or any other good books).
Besides try to practice previous years JAM and JEST question papers and if posible try any NET or GATE books.
Best wishes from my side and thanks for reading!