Which nameservers you use depends on which platform manages your DNS.

PlatformNameservers
WHMCS
portal.ozhosting.com
ns1w.ozhosting.com (103.23.153.87)
ns2w.ozhosting.com (203.83.245.201)
Odin - Legacy Platform
my.ozhosting.com
nsa.ozhosting.com (116.213.2.70)
nsb.ozhosting.com (116.213.2.71)
nsc.ozhosting.com (119.81.99.250)

Don't mix them. Use either the WHMCS set or the Odin set, not a combination. If you manage DNS records in portal.ozhosting.com, the domain must use the WHMCS nameservers. If your domain already works on the Odin nameservers and you don't need to change any records, leave it as it is.

Moving DNS from Odin to WHMCS: create the DNS zone and all its records in portal.ozhosting.com first (copy every A, MX, CNAME and TXT record), then change the nameservers. Changing nameservers before the records exist will stop your website and email. If you're unsure, raise a ticket and we'll do it with you.

Nameserver changes can take up to 24 hours to take effect.