Hi Rakshitha,
Hope you are doing well. In K-CET 20,000 rank is also considered as a good rank and you will get a seat in a comparatively good engineering college. But don't expect seats in top colleges like R.V. College Of Engineering and such. By this rank, you will be getting a seat in Dayanand Sagar Academy Of Technology, Vidya vardhaka college of engineering Mysore, Nitte Meenakshi Institute Of Technology and so on. Just go to the KEA website by clicking on the link below and download the previous year engineering cutoff rank list and search for each colleges and branch corresponding to your expected rank.

http://www.kea.kar.nic.in/cutoff.htm

I hope you got the point after reading this answer.

All the best.