This is his response to my mom : " f*** you and f*** my father it's all your fault for raising a leach ".

This is going to be cold and heartless, but ... he's not wrong. A very large portion of your brother's problem is your dad. Your father has gleefully funded every bad decision your brother has made. He's funneled money and time into Mike time and again, even when Mike has proven he's not trustworthy. Mike hasn't actually stolen anything - whatever he's blown away he was given.

Now, Mike is definitely a lazy, entitled, selfish asshole of a son who is ruining his and his parents lives. But don't delude yourself into thinking he did this alone.

Unfortunately, you can't go back in time and make your father be smarter with his money. He and your mother are just going to have to accept that their money is gone, and try to downsize their lives as much as they can. Hopefully, you and your other siblings can help. They should be in counseling to sort out their problems as well. Mike needs to be cut off financially and kicked out. He can get a job or starve.

Sadly, there's little you can do other than encourage your parents to start making better decisions and be there for them emotionally. You can't change your brother (though you can sure give him a talking-to) and you can't change them (though you can push for them to get therapy and help).