STEP 1. Log in to your Terminal
STEP 2. Click DNS Management > Reverse DNS Records and select bulk upload tab. Then select what type of IP addresses you wish to upload (IPv4 or IPv6).
STEP 3. Open any text editor like Notepad++, Notepad or any other preferable and fill in records in the following format:
Save rDNS records list as CSV file. See image below for example:
STEP 4. Use Terminal -> DNS Management -> Reverse DNS records -> Bulk tool -> Choose File button to select saved rDNS file from your computer to set new PTR records.