Plz suggest me the best topic from p block chapter from which the questions generally comes in jee mains and board .

Hey Chinmay
As you know that inorganic is not a small subject ( and P block is most important )
And there are a number of ways in which a question can be ask and there is number of concepts also.
So it is not easy to tell all the questions here.
But generally you should remember the main concepts and the pattern of the p block elements like reactivity comparison; strength comparison ; reaction with different elements ; states etc.
So I would suggest you to go through NCERT and xam idea and  then solve op Tandon .
Try to think and analysis the concepts behind every question and relate it with general variation of properties of elements.
So good luck