Wrap notices bit in one div, and float it left - then wrap the conditional adsense code in another div and float it right. You will probably need to play around with this. I don't have time to fine tune it but below is the rough code. Google "CSS style guide" or something like that if your not sure how to tweak the divs.
Code:
{vb:raw ad_location.ad_navbar_below}
{vb:raw ad_location.global_below_navbar}
<vb:if condition="$show['notices']">
<div style="float: left">
<form action="profile.php?do=dismissnotice" method="post" id="notices" class="notices">
<input type="hidden" name="do" value="dismissnotice" />
<input type="hidden" name="s" value="{vb:raw session.sessionurl}" />
<input type="hidden" name="securitytoken" value="{vb:raw bbuserinfo.securitytoken}" />
<input type="hidden" id="dismiss_notice_hidden" name="dismiss_noticeid" value="" />
<input type="hidden" name="url" value="{vb:raw return_link}" />
<ol>
{vb:raw notices}
</ol>
</form>
</div>
</vb:if>
<vb:if condition="is_member_of($bbuserinfo, 6)">
<div style="float: right">
// adsense code
</div>
</vb:if>
I find it useful to wrap adsense in a div anyway, just to help formatting incase its slow to load. On a side note, you realise adsense advertisers technically pay for content ads (e.g. an advert next to an article, or a forum post). Technically this may be in breach of adsense ToS since this will appear on all pages, not just those with content. However, many users do have non-content adsense ads (google don't seem to enforce this policy too strictly) but never the less be aware of it.