-Any free software that comes with a product will always be found on the respective product page, under the 'downloads' tab. For downloading Tracktion you must register first, please see further down the page for details.
For example for the Xenyx 302 USB, all of the free software would be found at http://www.behringer.com/EN/Products/302USB.aspx then under the downloads tab pictured below:
TIP: Using the Search Box on the site is a quick way to get to a product page (Located on the Top Right of the website)
The free software will be in the section called 'APPS' (as shown below).
-To obtain the free OEM version of the DAW/Sequencer/Audio Recorder software Tracktion, (as long as your product comes with Tracktion) simply go to the Support Page and register the details of your product, a redemption code will then automatically be sent to your registered email: http://www.behringer.com/EN/Support/Registered-product.aspx
-Once you receive the code all you need to do is go to the Tracktion website and click the Redeem Behringer section (pictured below), then just fill out the details to receive your free OEM version of Tracktion.
How can I tell if my product comes with Tracktion?
On your respective product's page on the Behringer website it will state in the 'Overview' section if your product comes with Tracktion as shown below (this is from the Xenyx 302USB page which does come with Tracktion):