I would imagine this can be easily accomplished through your site's css files? Google auto ads get wrapped in a div element with the class name "google-auto-placed". You could set that to display:none in your css file. So to keep the auto ads out of a division area with id name "no-ads", you could do something like this:

#no-ads > div.google-auto-placed {‌
display:none !important;
}

https://support.google.com/adsense/forum/AAAAKDuOfxQUjfjCFxvIBw/?hl=en&gpf=d/topic/adsense/UjfjCFxvIBw