Apex domains cannot have CNAME records.
Question and response
Question
dig junis.ni.AC.RS. NS
Answer
junis.ni.ac.rs. 5 NS ns2.junis.ni.ac.rs.
junis.ni.ac.rs. 5 NS ban.junis.ni.ac.rs.
Authority
The response has no authority records.
Additional
ban.junis.ni.ac.rs. 5 A 160.99.1.1
ns2.junis.ni.ac.rs. 5 A 160.99.1.2
ban.junis.ni.ac.rs. 5 AAAA 2001:4170:2801:0:0:0:0:1
ns2.junis.ni.ac.rs. 5 AAAA 2001:4170:2801:0:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0