Yes you can have a custom rDNS on your dedicated servers, VPS aswell as your additional/dedicated IPv4 and IPv6 assigned.
Please make sure you have a valid A or AAAA record set for the hostname you wish to add in your PTR/rDNS.
For Cloud VPS you can set your rDNS once you have a valid A or AAAA record from the SolusVM Control Panel.
Just contact us over a Support Ticket and we shall have it done for you.
- CSpace Hostings / https://cspacehostings.com