Hello.
For getting directly into Manipal Jaipur there are separate policies, a candidate must be a rank holder of JEE mains and should have cleared JEE advanced, or the candidate must be  MET rank holder, with this candidate must have at least 50% marks in class 12th with necessary subjects, generally with these criterias you can take direct admission in courses where the seats have been filled, you can check through the below link:

https://jaipur.manipal.edu/muj/admission/indian-students/admission-procedure.html

but if you are going to take admission on the basis of class 12th and you are not eligible in either of the criteria then the option is of management quota.
Best of luck.