What is the best ML/DL model to choose to calculate mobile network utilization increase
I do not see why having a percentage greater than 100% might be a problem to you? You might normalize it by dividing by 100, so 100% might become 1. That feature will be your label.
I suggest you try several regression algorithms, with different settings, and choose the best model i.e. the model which provides the best result. You have a bunch of regressors in scikit learn, you may also try XGBoostRegressor or CatBoostRegressor.