If you mean moving data from an NTFS-formatted volume to a HFS+-formatted volume, yes, you can do it without losing data.
If you mean reformatting an NTFS volume to HFS+, no, you cannot do that without losing the data on that volume.
If you mean moving data from an NTFS-formatted volume to a HFS+-formatted volume, yes, you can do it without losing data.
If you mean reformatting an NTFS volume to HFS+, no, you cannot do that without losing the data on that volume.
How to do what? You haven't specified whether you are just moving files from an NTFS volume to a HFS+ volume, or if you want to reformat an NTFS volume into HFS+ format.
Sure easy. Just open the Finder (icon below on the Dock) and navigate to the folder you want to move the files to.
Now hit command-n to open a new Finder window and drag it over so the Finder windows are side by side. Now in the second window select your NTFS drive on the left where it says Devices and navigate to the folder you want. Now just mouse drag the files you want from the NTFS drive to the folder on your Mac you have open in the first Finder window.