Greetings Abhrajeet!

Hope you're doing great.

Since you're asking this question, I'll assume you're a non KV student. Let's discuss the matter, Kendriya Vidyalaya is a central government based school and one of the largest covering every corner of the country. The admission into KV school is based on preference and yes, civil too can get admission unless seats aren't available. The hierarchy priority of occupation of the ward's parent is as follows:

Central government employee > Defence > Government employee > Child's quota > Civil Salaried > Civil Self-employed

I'm sure things will become pretty clear from this point, to get admission in KV one need to have luck factor as well. You might be brilliant in studies and might perform exceptionally well in the written test. But it'll not ensure admission, PERIOD! Talking from personal experience, I was denied admission due to a shortage of seat. So be prepared. For more details regarding the admission process visit the official website.

Best of luck!!

Hope, you'll find this useful. Do reach out in the comment section in case of any query.

Cheers!