Your hard drive is formatted in a certain way, which can vary depending on the device. Modern macOS use "APFS" for internal drives, for example, which cannot be recognised by Windows without additional software. However, if you remove a hard drive from a Windows PC and reconnect it to a Windows machine via USB using this adapter, the hard drive will of course be recognised without any problems.
Yes, you can use this adapter to read data from a 6TB hard drive without having to format it first, so that your important data is preserved. The adapter supports SATA HDDs and SSDs up to at least 12TB (in some cases up to 20TB) and is compatible with 3.5" and 2.5" hard drives, including the necessary power supply for 3.5" drives.
The connection is plug & play, no drivers are required and the hard drive can be read directly as long as the file system is recognised by the operating system. It is important to safely eject the hard drive before removing it to avoid data loss.