Hello Sudheshna,

Hope you are doing well.

First of all, you need to qualify in all the subjects as per the cutoffs which vary according to the entrance exam. Since, you have not mentioned which exam you are talking so I will be giving my answer in general. Suppose, you and another student got same marks then while ranking the subject preference comes. If you got more marks in X subject than other student, so your rank will be automatically higher than him. But which subject is preferred first depends on the board who conducts the exam and gives the result.

Good Luck.