Dear candidate, there is maximum probability that you will qualify jee mains and will be eligible for jee advanced after getting 100 marks in jee mains. However, as exams are conducted in various shifts with different question papers, different types of students sitting in different shifts, which means difficulty of paper varies with number of students in every shift so cutoffs may vary but mostly students qualify jee mains by getting 90+ marks in jee mains.

Hope, it helps!