Categories in two columns

I am trying to split the categories into two columns with each category showing articles’ title as a list.
I have searched the forums and what I have found mostly is this code below, however, it doesn’t say where or which file to put it in, it says put it where you want it! I put it where I want it, for example right on front.php and it is not working, Other thing I noticed in my WP version (3.3), wp_list_categories is deprecated. That must be why it is not working. Does anybody have any idea what should be replaced and where the code goes please. Also how to add the title of say only 6 articles under each category as a list? Thanks so much ??

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