mx01.ntc.net.pk has no NS records.
NS records for this zone are defined at ntc.net.pk.
NS records for this zone are defined at ntc.net.pk.
Question and response
Question
dig mx01.ntc.net.pk. NS
Answer
The response has no answer records.
Authority
ntc.net.pk. 600 SOA ns3.rapidcompute.com. dns-services\@cyber.net.pk. 2019031037 600 60 604800 600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0