There is nothing anyone on the RealmEye Forum can do about hackers and cheaters. RealmEye is not part of Deca, and we don’t have any in-game powers. We’re regular players, just like you.
Instead, send your report to Deca. They have a support topic about cheating, and they ask that you use their Submit a request to send in reports. Be sure to choose “Report Cheat / Exploit” for the Category.
Setting up your evidence
The most important part about evidence is that it’s conclusive. The more conclusive the evidence is, the faster Deca staff can work through it. This is even more important considering the limited number of people working in Support.
Screenshots aren’t ideal, because they can be easily manipulated and they don’t capture the entire situation. This makes screenshots unreliable, and can leave out important information that disproves the evidence.
This leaves us with recordings. This is an example video I used for a report. It provides multiple instances of evidence of them using various cheats, just to be sure their cheating becomes obvious even if I made a mistake on a few of them. In the description I organized by the person using the cheats and put timestamps for all those instances with a short description of what you can see. This is necessary for in longer videos or videos where a lot of things are happening so Deca can efficiently view the evidence and take action based on it. Sending in an hour long video with just “they’re all cheating” probably wouldn’t get any reaction out of Deca.
Don’t let that discourage you. Your reports don’t always have to be this detailed. It simply serves as a great example on how to set it up. A video of a single guy just ignoring unstable at an Avatar or noclipping through a wall is often more than good enough.
As an alternative to recording videos /u/Mrunibro made a comment about recording gifs with Gyazo. Read it here for a short explanation of what you can do with it and how you do it. I’m sure he’ll also gladly help you if you have more questions about it.
tl;dr: Make conclusive evidence, send it to support, don’t harass people.