Apex domains cannot have CNAME records.
Question and response
Question
dig VNIIFTRI.RU. NS
Answer
vniiftri.ru. 5 NS ns4-l2.nic.ru.
vniiftri.ru. 5 NS ns8-l2.nic.ru.
vniiftri.ru. 5 NS ns.vniiftri.ru.
vniiftri.ru. 5 NS ns1.vniiftri.ru.
Authority
The response has no authority records.
Additional
ns.VNIIFTRI.RU. 5 A 89.109.251.18
ns1.VNIIFTRI.RU. 5 A 212.248.75.98
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0