You can use rekordbox or Serato DJ Pro while your computer is connected to the DDJ-FLX6.

To use all the features of rekordbox or Serato DJ Pro, you'll need to subscribe a relevant rekordbox plan or purchase Serato DJ Pro Expansion Pack.

■rekordbox

See [here] for the features available through Hardware Unlock in rekordbox.

■Serato DJ Pro

You can use Serato Pitch 'n Time DJ and Serato FX.

For Serato DJ Pro, see [here].