Hi

Karnatake Exam Authority conducts KCET only for karnatake locals or residents. All the 100% government seats are only for karnatake resident students. KEA has set up domicile criteria to determine if candidate is eligible to answer KCET. You can go through the below link for detailed information about domicile requirement.  

https://engineering.careers360.com/articles/kcet-eligibility-criteria

However , for non karnatake residents who are seeking admission into karnatake can answer COMEDK. Any Indian citizen passing 12 std can answer COMEDK.