List main folders that contain non changed folders and files since a specific date
cd &lt;to directory containting the main folders&gt;
for d in */; do
    if [[ $(find "$d" -mtime -26w | fgrep -v .. | wc -l) -eq 0 ]]; then
        echo "$d"
    fi
done


should work, with the usual caveat about file/directory names containing newlines etc.

mtime compares the modification timestamp of the file with "now", -26w means "less than 26 weeks" (which is roughly 6 months).