Question

How I could calculate gravitational potential energy fromEinstine field equations

Answer 1

Answer

we define according to concepts of physics the change in gravitational potential energy ΔPE_g to be 

ΔPE_g = mgh

for calculation easy we denote the change in height by h rather than the usual Δh. Note that h is positive when the final height is greater than the initial height, and vice versa.