2620:101:2012:300::3f9

Reverse address entry: 9.f.3.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.2.1.0.2.1.0.1.0.0.2.6.2.ip6.arpa

2620:101:2012:300::3f9 has no DNS entries .

Explore by label: 9 . f . 3 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 3 . 0 . 2 . 1 . 0 . 2 . 1 . 0 . 1 . 0 . 0 . 2 . 6 . 2 . ip6 . arpa

RIPE6 9.f.3.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.2.1.0.2.1.0.1.0.0.2.6.2.ip6.arpa
CNAME9.f.3.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.2.1.0.2.1.0.1.0.0.2.6.2.ip6.arpa.eu.iphmx.com expired since 1 week, 3 days
Show 1 expired records

This top-level domain has no publically available whois server. Try going to www.nic.arpa.