The eligibility criteria says you may appear in the exam if  have studied and passed from a recognised institution situated in Karnataka, with the academic study of at least 7 years this is the basic domicile requirement to be fulfilled to learn about academic requirements you can go through https://engineering.careers360.com/articles/kcet-eligibility-criteria 

I suggest you to go for COMEDK instead their rules aren't as strict as KCET and you can go for some great private colleges out there but the only disadvantage is with comedk your fees will reach upto 2 lakhs per annum as comparred to fees of KCET that is 80-90k.

All the best!!