Hello,
In case, your college takes admission based on the merit list then yes, your class 12th marks will be considered important while the calculation of the merit list. Merit list is usually a list of students along with their class 12th marks. The students with the highest class 12th percentage is on the top while the students with lower percentages are below. It is a ranking system.
Thus, such ranks can only be taken out based on your marks in class 12th board exams.
I hope this helps,
All the best
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