Apex domains cannot have CNAME records.
Question and response
Question
dig yottavdi.com. NS
Answer
yottavdi.com. 4 NS ns2.yotta.com.
yottavdi.com. 4 NS ns3.yotta.com.
yottavdi.com. 4 NS ns1.yotta.com.
Authority
The response has no authority records.
Additional
ns1.yotta.com. 4 A 103.151.97.4
ns2.yotta.com. 4 A 103.151.97.5
ns3.yotta.com. 4 A 157.119.229.230
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0