Whatever the collateral percentage is and whatever the yearly returns is, there's literally NO WAY I'm going to lend money to a telegram group. Imagine a scammer so bad at stealing money that they don't even bother to spend some money to rent a server and start a website.
Not only that! If indeed it turns out to be scam, then there is no way he can recover his funds because he is dealing with mostly anonymous individuals with no known office address, identities, etc., which in short, he is dealing with ghosts!
Maybe he can file a legal complaint but I'm sure he will just be naming his respondents as John Doe's and Jane Doe's!