As the ranks and cut offs aren't out yet, so it is hard to tell because ranks are subjected to change every year as it depends upon various factors like number of applicants fill the form, number of applicants finally appeared in the exam, number of questions asked in the exam, difficulty level of the exam, performance of the candidate, previous year's cut offs trends but according to results of 2017 I think with 20 marks in KCET you'll be getting a rank around 15-16k.

All the best!!.