My dad is 2 weeks into coma after brain hemorrhage operation. What are his chances of survival?

He is not opening his eyes and on ventilator support, though he could breathe naturally when ventilator was taken off recently for 2 hours. He has no other movements. His heart, kidney and gastric systems are working fine so far. He sufferred a stroke (8.5 cm blood clot) 2 weeks back. Pls respond with anything that can help. Thank you.