there are many forces. air pressure is one. spinning creates more air pressure.
Since the earth is an ellipsoid, the distance to the center of the earth is greater in S.K.
Since S.K. is closer to the equator, the linear velocity of S.K. is greater than the linear velocity of N.K.
If you are talking about straight gravity, then the answer is South Korea.
If you are talking about NET gravity taking the lift force on the spinning surface and subtracting it from the gravitational force pulling in the opposite direction, then I'M NOT SURE.
Since the two Koreas share a common frontier, the difference that we are talking about is miniscule.
a scientist is basically a gay wizard. gravity does not exist
Pyongyang, North Korea: 9.80072 m/s^2
Seoul, South Korea: 9.79942 m/s^2
So a person would weight about 0.013% more in North Korea. The difference depends on exactly which places you compare.
I read somewhere that the oceans water collect more near the equator where billions of more water collect. With this in mind there is more pulling than pushing at these locations. So I will say North Korea has more gravity pushing down on it.
Your weight as measured on a scale would be slightly greater in Norh Korea since you are closer to the center of the Earth due to the equatorial buldge. Also, less of the force of gravity is used to provide centripetal acceleration since you are closer to the axis of rotation.
The earth is flat, so gravity is constant throughout
There is NO levity in North Korea, therefore much more gravity.