Apex domains cannot have CNAME records.
Question and response
Question
dig nren.net.np. NS
Answer
nren.net.np. 5 NS ns.nren.net.np.
nren.net.np. 5 NS ns.lahai.com.
nren.net.np. 5 NS puck.nether.net.
nren.net.np. 5 NS ns.ds.net.np.
Authority
The response has no authority records.
Additional
ns.ds.net.np. 5 A 202.53.1.2
ns.lahai.COM. 5 A 206.220.230.130
puck.nether.NET. 1 A 204.42.254.5
puck.nether.NET. 1 AAAA 2602:fe55:5:0:0:0:0:5
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0