Hello Kiran,

I would like to tell you that there isn't any particular thing that is important in polymers.

You would have to do the whole chapter and the chapter has a weightage of  3% of total questions or around 3-4 questions.

For more info on weighatge, I would suggest you to visit the career360's link given below:

The link for the same is:https://medicine.careers360.com/articles/neet-chapter-wise-weightage-and-important-topics

Hope that helps and all the very best!