Apex domains cannot have CNAME records.
Question and response
Question
dig tes.com.pk. NS
Answer
tes.com.pk. 5 NS ns1.tes.com.pk.
tes.com.pk. 5 NS ns3.tes.com.pk.
tes.com.pk. 5 NS ns2.tes.com.pk.
tes.com.pk. 5 NS ns4.tes.com.pk.
Authority
The response has no authority records.
Additional
ns1.tes.com.pk. 5 A 45.249.11.6
ns2.tes.com.pk. 5 A 45.249.11.7
ns3.tes.com.pk. 5 A 117.20.24.103
ns4.tes.com.pk. 5 A 45.249.9.45
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0