Considering your COMEDK rank as 12989, you have chances to get a CS seat in more than 100 colleges some of which are listed below:

• BNM Institute of Technology, Bangalore
• CMR Institute of Technology, Bangalore
• JSS Academy of Technical Education, Bangalore
• KLE Technological University, Hubballi
• Mysore College of Engineering and Management, Mysore
• Dayananda Sagar Academy of Technology and Management, Bangalore
• Kalpataru Institute of Technology, Tumkur
• Acharya Institute of Technology, Bangalore
• SJB Institute of Technology, Bangalore

To know the names of rest of the possible colleges for you , you can use COMEDK UG predictor tool 2019.The link for the same is:

https://engineering.careers360.com/comedk-college-predictor

Best wishes!

Hope it helps!