To answer your question... try to search for websites being advertised ion orkut first (if there is) and take a look if they have adsense..
Hello I think No need to promote Via orkut because it's community for every body Here in orkut people information is not 100% trusted so try to avoid promoting website via orkut.
As orkut is a social community, i think it is better not promoting your website in orkut.. Try advertising using different methods like free classifieds, directories, genuine link exchange etc.. this would be better rather than that..
Yea you can, I know a few sites that get quite a bit of traffic from orkut. But orkut is mostly Brazil type traffic.