Most students consider campus to be quite diverse. With students from all over the country, not to mention the world, there's a little bit of everything. Virtually every ethnic group on campus has multiple organizations that its members can get involved in and spread awareness of different cultures. There is also a great range of social and economic backgrounds among the students at RPI.
Because it is primarily an engineering school, however, most of the students at RPI have similar interests and hobbies. This can make it seem like the campus isn't as diverse-although there may be a broad range of people, the number of cliques is somewhat narrower. You see a lot of people hanging out with groups of similar backgrounds, and while the groups don't clash, there isn't a tremendous amount of intermingling between them.