Hey,
I've just (more or less) finished my Keylab 25 remote mapping file for Reason. I'm running Reason 10.2, but it should work for reason 9 etc too. I've only mapped the sliders and knobs, as getting the buttons to work was hit or miss unfortunately. I only own the Keylab 25, but I hope that the mapping is similar enough so you can just change the name of the file to work with your controller.
You place the linked file into this directory in Windows: C:\ProgramData\Propellerhead Software\Remote\Maps\Arturia\
In the latest version of Reason, after you've put this file in the right place with a name that's matching your specific Keylab model, just delete your current control surface configuration in Reason, then click on "Auto-detect surfaces" and it should be found and get the green check mark. If you're not using a Keylab 25 and it's not working, then you may need to edit it yourself.
If you have a soft synth, VST effect or Reason Extension that's not included in my attached file, you can add them yourself using the below formula.
Note: You have to use TAB, not space while formatting it, or Reason will show you an error which line is faulty. There are no spaces between Map and category for example, but a TAB. Or else...
// (Here you can enter a CLEAN NAME OF REASON INSTRUMENT, VST SOFT SYNTH OR EFFECT. The "//" means it won't be read as code by the application but as a comment.
Scope manufacturer and name of instrument or effect that have to get by exporting the data from reason
Map category
Map preset
Map volume
// Bank 1 knobs
Map cut
Map reso
Map lforate
Map lfoamt
Map chorus
Map param1
Map param2
Map param3
Map param4
Map delay
// Bank 1 sliders
Map atk1
Map dec1
Map sus1
Map rel1
Map atk2
Map dec2
Map sus2
Map rel2
Map fader9a
// Bank 2 knobs
Map cut2
Map reso2
Map lforate2
Map lfoamt2
Map chorus2
Map param1b
Map param2b
Map param3b
Map param4b
Map delay2
// Bank 2 sliders
Map atk3
Map dec3
Map sus3
Map rel3
Map atk4
Map dec4
Map sus4
Map rel4
Map fader9b