I think you are mistaken by saying 10.6 iOS...
Mac OS X 10.6 is Snow Leopard, iOS is the software on iPhone/iPad/iPod (models).
I would advise you to create a backup using Time Machine, then upgrade to Mavericks, being safe with all your data.
For more information about Time Machine, see:
It is very smart of you to create a backup of your 10.6 system before upgrading to Mavericks 10.9.
I highly suggest creating a external BOOTABLE backup of 10.6 onto a blank POWERED external drive.
Your going to find out that 10.9 will NOT run your older 10.6 software, especially anything with PowerPC code.
Also your uprade could fail, or you might not like the new UI or the slow performance of Mavericks, which the external bootable clone of 10.6 will allow you to boot from it, erase the ENTIRE internal drive in Disk Utility and reverse clone 10.6 back onto the internal drive.
This is by far the best method, TimeMachine restores are flaky because one cannot test them by booting to see if all works as expected for later restoring, but with a bootable clone, one can.
Here is a step by step instructions, good luck.