Assuming you are asking for Paper 2 and NATA so both do not consider 12th marks and the admission will be done on the basis of ranks only and the rank will be out on the basis of the exam score. You can check the exam pattern below -

Jee Main Paper 2 -

Question Paper Details -

Mathematics (Part 1)– 30 Objective Type Questions

Aptitude Test (Part II) – 40 Objective Type Questions

Drawing Test (Part III) – 2 Questions testing drawing aptitude of candidate

Total Marks - 390

Marking Scheme - Part I & Part II Each question carries 4 marks

For every incorrect attempt, 1/4 marks will be deducted.

Part III - 2 questions carrying 70 marks. The marks alloted to the two questions will be displayed alongside the question.

NATA -

Total Marks - 200

Distribution of the Questions - 60 questions in Part-1 & 2 questions in Part-2

Number of Questions - 62 and there is no negative marking.

Note : On the basis of above exam pattern, the rank will be out.

Hope this helps!!!