The obvious choice for dft to par conversion is Solid Edge software, from which both of these CAD format originate. Some viable alternative would be to use some 3rd party software with support of Solid Edge formats, but it's usually better to use the original software.
Convert Solid Edge drawing file to Solid Edge part CAD file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert dft to par on Windows
A feature rich 3D CAD software by Siemens
Convert from dft file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.