If the file system on the drive is NTFS, then that is why macOS cannot modify it. macOS can only read NTFS volumes by default. It is best to only use a file system that macOS supports natively such as exFAT if the drive needs to be shared with Windows, otherwise use a macOS file system such as MacOS Extended (Journaled) or APFS. APFS is only compatible with Macs running macOS 10.13+, so if the drive needs to be used with older Macs running older versions of macOS, then use MacOS Extended (Journaled).
Why do you want to partition a drive? How are these partitions going to be used? I highly discourage this practice because people usually end up with major problems later on when they discover that one or more partitions don't have enough space.