I'm not sure when that printer was made, but slightly older HP drivers are notorious for not playing well w/ OS X (at least from my experiences)
The HP may not show up in the initial printer selection window when adding a new printer, rather you may have to click on the "More Printers..." button at the bottom of the Printer Browser window.
Following that you would then need to click the drop down menu at the top of the more printers box, it has options like Windows Printing, HP IP Printing etc...
Ignore those and look for your 6200 in that list, it may take a moment to pop up in there though. That was always the proceedure for my Photosmart 7550 (support for which is now broken in Leopard)
Also it would be helpful to know what OS you are running.
There is also a great 3rd party driver available that I used to get my Photosmart 7550 working in Leopard that may help you.
The Driver can be found here:
http://www.linux-foundation.org/en/OpenPrinting/MacOSX/hpijs
You will also need to install FooMatic and Ghostscript FIRST for the driver to work properly. They are located just below the driver on that download page I just linked you to.
Info on your specific printer working with this driver can be found here:
http://openprinting.org/show_printer.cgi?recnum=HP-OfficeJet_6200
Best of luck.
