If diet is correct enough, then without doing exercise weight will go to its correct range and remain there. That should be around 15-18%, body fat percentage.
If overweight, exercise is not needed to lose weight (though it can speed it up). It will correct itself with just diet. Or if underweight, then will gain weight, and still to the correct range.
If you add just exercises, and are already around 15-18%, it might lower your weight (body fat) by very little. Or might also increase it through building some more muscle, also just by a little bit. So in this regard not much change, if at all, weight wise.
If you actually train, well and correctly, then you will gain weight as muscle mass, and your body fat percentage might go to around 10% or a little bit lower.
