Hello Student , as the cutoff and the marks range and rank vary every year due to some unavoidable reason, for the number of competitors is growing day by day,  difficulty level of questions is growing high, number of qualifying students also growing high. So if you do not specify your category it is not easy to mention the marks and rank in KCET. According to previous years trend it may be said that-

To Get  rank above 8000 in KCET student has to score at least 85% to 90% marks in 12th class examination and 100 to 110 marks out of 180 marks  to get the rank above 8000