ave a 2011 ford escape 3.8 awd tried to take off seems like the rear end locked up is this a transfer case problem or axle problem
Yes. Either could be the issue but can’t be diagnosed over the internet! The car needs to be on a lift and some things need to be disconnected - the rear driveshaft, for example - to determine if the rear axle turns or not. Then the investigation leads to the transfer case. Does the front axle turn? Does the rear driveshaft feel locked up?
Or it could be a stuck caliper or parking brake in the rear. Or it could be a failed rear wheel bearing. Lots of great chances for failure. If you are going to tackle this yourself, get all 4 wheels up in the air and the car safely on jackstands and start working your way around. Otherwise, it needs to be towed to a good independent mechanic.