Apex domains cannot have CNAME records.
Question and response
Question
dig REDCOM.RU. NS
Answer
redcom.ru. 2 NS ns1.redcom.ru.
redcom.ru. 2 NS ns.redcom.ru.
redcom.ru. 2 NS ns8-l2.nic.ru.
redcom.ru. 2 NS ns4-l2.nic.ru.
Authority
The response has no authority records.
Additional
ns.redcom.ru. 2 A 212.19.2.1
ns1.redcom.ru. 2 A 212.19.3.1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0