If you are planning to lease your subnet (sometimes also called as IP range or prefix) on Heficed's IP Address Market, you would firstly need to change the delegation for this prefix to Heficed's nameservers, which would enable rDNS to be controlled via Terminal.
Here are the steps of creating delegations (creating domain objects) if your IP address was issued by APNIC RIR:
Log in to MyAPNIC via https://myapnic.net/
Select "Resourses" tab
3. Select "Add Reverse Delegations" under "Reverse DNS Delegations"
5. Select the maintainer (if not autoselected) and press "Next"
6. Add the description, your admin and tech contacts, then press "Save"
The domain object is now created and can be seen at Resources> Reverse DNS Delegations> Reverse Delegation Summary.
Take notice that APNIC only permits delegations of /8, /16, and /24 for IPv4 reverse delegations. For example, to register a /15, you need to register two /16 objects. To register a /20, you would need to create sixteen /24 reverse domain objects.
In the picture above you can see one IP subnet of /23 created, yet on the right side you can see 2 Domain Objects Registered, as /23 = 2 x /24
For more information, visit https://www.apnic.net/manage-ip/manage-resources/reverse-dns/access-to-reverse-dns/new-domain-object/