Assuming all other things are equal, if you use a manual mode to set an exposure suggested by the camera's internal light meter, it should produce an equivalent result to one which was selected by the camera's internal automatic/program exposure mode.

The difference would be that, in the camera's automatic mode, a pre-programmed series of aperture and shutter combinations is used to select the right exposure for that shot whereas, you get to choose the aperture/shutter combination, yourself, in manual mode.

That is what "manual mode" is for. It allows you to use selective focus, via depth-of-field adjustments, and to freeze or blur action, via shutter speed adjustments, to compose the picture the way you want it to look yet still get an acceptable exposure without having to fuss too much.