Apex domains cannot have CNAME records.
Question and response
Question
dig ural.rt.RU. NS
Answer
ural.rt.ru. 5 NS ns1.rostelecom.ru.
ural.rt.ru. 5 NS ns1.ural.rt.ru.
ural.rt.ru. 5 NS ns2.rostelecom.ru.
ural.rt.ru. 5 NS ns2.ural.rt.ru.
Authority
The response has no authority records.
Additional
ns1.rostelecom.RU. 5 A 87.226.162.62
ns2.rostelecom.RU. 5 A 87.226.159.65
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0