You may set the PTR / rDNS record for both your IPv4 and IPv6 addresses assigned to you. Doing so is quite easy.
Step 1: Login to your VPS control panel here: https://control.incogvps.com:4083/
Step 2: Select, "Reverse DNS" from the sidebar menu.
Step 3: Select the IP address from the drop down menu that you want to set the record for.
Step 4: Enter the FQDN / domain name for the record in the area below the IP address selection and then click, "Add Reverse DNS"
Feel free to use a tool like https://www.whatsmydns.net/dns-lookup/ptr-records to check that your record has taken hold. Often the records are shown almost instantly after submission. If it's been an hour or more and your PTR record still isn't showing globally, please contact us.