Inside post is no option.
Between posts yes:
In "Edit ads", in mod's configuration window, click your ad and then in the place were is "Display ads within posts" put the number from the posts after the ad should appear (with comma).
If you pot 1,5,8 then your ad will appear after the 1st the 5th and the 8th post.
If you want that your ads look like ordinary posts then check the "Ads within posts look like actual posts" in "Settings" window from the Ad Management Administration.