Apex domains cannot have CNAME records.
Question and response
Question
dig sify.net. NS
Answer
sify.net. 5 NS sdns.satyam.net.in.
sify.net. 5 NS sdns.sify.net.
sify.net. 5 NS pdns.sify.net.
sify.net. 5 NS pdns.satyam.net.in.
Authority
The response has no authority records.
Additional
sdns.satyam.net.in. 5 A 202.144.63.4
sdns.satyam.net.in. 5 A 202.144.63.12
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0