Hello, 

I have made a list of few topics which have a higher weightage as compared to other topics

1. Thermodynamics

2. Optics: Ray Optics and Wave optics.

3. Electrostatics

4. Electronic Devices

5. Current Electricity and Electromagnetic Induction.

All the topics in 11th and 12th physics are important but the above mentioned topics have a higher weightage. It is necessary to study all the topics but it's better to focus on these topics the most as usually more number of questions are asked from these topics are asked. 

Please visit the following website for more detailed weightage classification. 

https://medicine.careers360.com/articles/neet-chapter-wise-weightage-and-important-topics/amp

Good luck!