Apex domains cannot have CNAME records.
Question and response
Question
dig airtel.cy. NS
Answer
airtel.cy. 4 NS ns3.airtel.net.cy.
airtel.cy. 4 NS ns4.airtel.net.cy.
airtel.cy. 4 NS ns1.airtel.net.cy.
airtel.cy. 4 NS ns2.airtel.net.cy.
Authority
The response has no authority records.
Additional
ns1.airtel.net.cy. 4 A 62.228.228.4
ns2.airtel.net.cy. 4 A 172.233.62.46
ns3.airtel.net.cy. 4 A 62.228.228.6
ns4.airtel.net.cy. 4 A 164.90.219.22
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0