Hello, I'm very sorry to hear about your brother's accident.
Brain injuries are devastating, especially when they leave a loved one in a coma
I'm a bit confused by your saying his brain activity is at "3". Sometimes people mean that the Glasgow Coma Score is a 3, which means that there is no movement, no eye movement, and no attempt to speak. It represents very severe brain injury
Random eye opening and muscle twitching in the setting of massive brain injury are never good. They can mean anything from seizures to random discharges of a permenantly damaged brain.
While 5 weeks is not a "long" time in terms of brain injury (especially in young patients), what you describe does not sound good. While there may be a chance for your brother to "awaken" it is likely very very small. If you are asking the possibility that he will ever be "normal", that I'm sorry to say is not a possibility.
It is not my intention to remove your hope of a miracle, but I want you to know where your brother stands in relation to others with similar injuries. My prayers are with you and your family.