Apex domains cannot have CNAME records.
Question and response
Question
dig telehouse.hc.ru. NS
Answer
telehouse.hc.ru. 5 NS th-ns2.hc.ru.
telehouse.hc.ru. 5 NS th-ns1.hc.ru.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0