What Are The Chances Of Recovery When Having Swelling And Pressure On The Brain

My brother had a heart attack and was given a huge dose of clot buster, saved his heart and had a stroke on left brain. Had 2 brain surgeries to relieve pressure and swelling, took out left flap. Was put under induced coma, had ventilator. Now he's on a trach, however has not woke up since then. What are his chances of a complete recovery.