Apex domains cannot have CNAME records.
Question and response
Question
dig nettivaraus.com. NS
Answer
nettivaraus.com. 5 NS ns1028.ui-dns.org.
nettivaraus.com. 5 NS ns1028.ui-dns.com.
nettivaraus.com. 5 NS ns1028.ui-dns.de.
nettivaraus.com. 5 NS ns1028.ui-dns.biz.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0