how many points are required to be written for a 6 marks question?

Debashis, it is ideal if you provide 6 points for 6 marks questions including a brief introduction and a short conclusion part at the end of the answer just to reinforce what your answer says. In case, if it is not mentioned in the question regarding the number of points, then also, it is adviseable to mention atleast 6 points. Do good in the exams!!