Hook to filter content before rendering in TYPO3 via Extbase?

Question

I need to filter content from tt_content by some criteria, before Typo3 renders it Probably by a hook.

Is there such a hook in typo3 6.1.6? And how can I use it?

Is it in

$TYPO3_CONF_VARS['SC_OPTIONS']['t3lib/class']['t3lib_pagerenderer']['php'] = '';

or

$TYPO3_CONF_VARS['SC_OPTIONS']['tslib/class']['tslib_content']['php'] = '';

I know How can I include and register my class in my extension, but what I dont know is where in TYPO_3_CONF_VARS in this case.

I have used the native category system and developed extension with plugin, which show content only from the selected category(ies). Now I need to filter content on each page, to dont display content, whis is in desired category. The desired category is setup in EM config