There is no fixed number which decides the KCET rank of a candidate for that particular year. There are factors on which the cut off for KCET Exam changes every year some factors like Number of Candidates appearing for Exam, Difficulty of Exam, Marks obtained in 12 Class etc…

But if you really want number i can give a round figure somewhere near the minimum marks needed to get Rank less than 800 in kCET:

Suppose you have taken the exam in 2019, to make your rank lie under the 800 a candidate may need to get around 160–180 Marks in KCET 2019 Entrance Exam and around 90–95% in 12 Boards.

But these numbers can changes based on above listed factors.

All the Best!!