In xat, should the maximum number of unattempted questions be 8 for each section or for the entire paper?

Okay thanks!

the negative marking for unattempted is way better than the negative marking of incorrect answer. Try to leave the 8 questions in your weaker sections and don't get bothered leaving more than 8 questions.

Oh okay thanks. Also, what is the best possible way to avoid negative marking in such a case?

nope, 8 out of 75