Apex domains cannot have CNAME records.
Question and response
Question
dig vdsina.RU. NS
Answer
vdsina.RU. 5 NS nssec3.vdsina.RU.
vdsina.RU. 5 NS nssec1.vdsina.RU.
vdsina.RU. 5 NS nssec2.vdsina.RU.
vdsina.RU. 5 NS ns4-l2.nic.RU.
vdsina.RU. 5 NS ns8-l2.nic.RU.
Authority
The response has no authority records.
Additional
nssec1.vdsina.RU. 5 A 109.234.33.32
nssec2.vdsina.RU. 5 A 95.142.47.163
nssec3.vdsina.RU. 5 A 178.62.209.191
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0