I know a few of these. from the top picture, starting from the back
The green/brown colored one is a fungie plate. It is not yet open. When it is open, it will let out 1/4 inch feeding tentacles. These can be semi aggresive. I would suggest this guy in the sand, and leave a clear area around it. It will "inflate" once it's happy and it will spread out beyond the size of the skeleton you see here. I have mine under direct lights and mild flow, nothing direct. Caution, these corals will fill up with water and move around the tank until they are happy.
next, looks like zoas? I can't actually tell but that is my best guess.
Next, the purple thing either looks like Green star polyps that are closed up or it also looks like a pipe organ coral? Do you have a clearer picture?
The one in the direct middle of the picture with all the little heads and green mouths looks like some Duncan corals. I have these and LOVE them. They will branch out and sort of make little colonies on the ends of the branches. I have mine under 150 watt MH, fairly close to the top of the tank. I would not say these are aggressive but I give them room. The tentacles can be short but then they will spread out and become long and flowing at times. They can easily touch other corals around them when they do this. I also like to feed mine pellets every few days or weeks. No specific food needs, I just like to grow mine.
The last one that I can identify is the green one that looks like a cone shape. Looks like you already have some in your tank. They're trumpet corals or candy cane corals. I have these and give them a little room but not a ton. I have seen some that have crazy sweeper tentacles. Mine do not. You'll have to watch them at night and see how much room they need.
