Reading through some of the trip reports around here and you'll quickly find accounts of interacting and communicating with entities in all kinds ways, whatever 'they' actually are...
The question of their 'reality' is an interesting one, that's for sure..and you'll get a wide variety of opinions here. Its something that's discussed endlessly and there is many good threads to poke around
Personally i feel that in some ways the dmt experience is pretty direct with what is going on, generally speaking. When thinking about it i'm usually reminded of when dennis mckenna was speculating about dmt being a kind of message encoded in the natural intelligence of nature, which is more like an organism than a mostly lifeless blob of ran-dumb processes, as humanity has typically envisioned it lately.
I mean here we have a simple chemical key found all over the place, including the human brain, that not only expands thoughts, feelings, love, and creativity in general, but at a certain threshold brings you into a direct experiential channel with other entirely different levels of reality, consciousnesses, aliens, machines, weird cities, non-locality, and all of this STUFF... The Mystery is a never ending conundrum locked in a riddle and dripping paradox... but in some ways, when it comes to the question of what DMT is doing in general, and I look back at my experiences and those of my companions, i can't help but feel like well...what could be less ambiguous than that?
Not that i believe all of this

. I try to leave belief out of it and remain open, even if i do have many suspicions. Plus my left brain has a hard time accepting any level of reality outside of its comfort zone. I've noticed that as the time between our last deep experience grows, and our ego has time to build its borders up, awareness of the immensity of its implications decays