Physics is a subject in NEET exam which becomes the deciding factor for your rank. Neet students generally are believed to be good in biology and chemistry but at times find physics difficult. So this is an area where you can give double your efforts to secure a good score. So I personally recommend you to cover as much as portion as you can. Anyhow I'll enlist down some of the important topics for neet 2020-

1. Ray Optics
2. Magnetic effects of electric current
3. Electromagnetic induction
4. Modern physics
5. Rotational motion
6. Waves and sound

Best wishes. Thank-you.