My brother had two brain bleeds, known as subdural hematomas, and two surgeries to fix them. He was unconscious for close to 6 wks. He was about 60 when this happened. He did recover very well, altho he had some memory issues about events in the past, he got them quite jumbled. A brain bleed can kill a person, so I hope you give your permission for him to have his surgery.
As for what happens after, I dont think any of us can predict that.