My father got T-Boned on the passenger side door on the freeway. His car is totaled. He has neck pain. What are our legal options?

My father was driving on the freeway and a car two lanes over lost control on the slippery road and spun 90 degrees, regained traction, and ran into the side of my dads car going very fast. He thought "Is this it?" when he saw the car moments before it hit him. His car is totaled, and he now has neck pain, has been feeling nauseous, and has been sleeping a lot. The two young ladies that hit him are fine, and have insurance (Progressive). What are our legal options? Mainly, can he sue? Is there any ways he can get a lot of money from this? Not that he would, I am just wondering so we don''t get stepped on.