There are some issues when you install both 32b and 64b versions of TC into the same directory and then you try to uninstall it. These issues depend on the order in which you install and then uninstall TC.
This is the proper behavior:
Install 32b version then 64b version
Uninstall 32b version - it is removed properly and 64b version is untouched
Uninstall 64b version - it is removed properly
A little bit buggy behavior:
Install 32b and 64b versions in any order
Uninstall 64b version - it shows a warning that it's going to remove 32b version too, however unrar9x.dll and desktop/start menu shortcuts for the 32b version are not removed
A wrong behavior:
Install 64b version then 32b version
Uninstall 32b version - it is removed properly, however 64b version is corrupted
Uninstall 64b version - all leftovers are removed properly