Apex domains cannot have CNAME records.
Question and response
Question
dig dotarai.com. NS
Answer
dotarai.com. 5 NS ns3.mail.in.th.
dotarai.com. 5 NS ns.mail.in.th.
dotarai.com. 5 NS ns8.mail.in.th.
Authority
The response has no authority records.
Additional
ns.mail.in.th. 5 A 202.28.1.60
ns3.mail.in.th. 5 A 117.18.126.149
ns8.mail.in.th. 5 A 194.58.198.32
ns8.mail.in.th. 5 AAAA 2a01:3f1:3032:0:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0