Fraction value after fitting sub-range

Dear Experts,

  I am fitting data histogram with a composite function to evaluate the signal and background contributions.

 RooRealVar coeffModel("coeffModel", "coeffModel", 0., 0., 1.);
 RooAddPdf sumModel("sumModel", "coeff*modelPdf1 + (1 - coeff)*modelPdf2", model_mc0Temp, model_mc1Temp, coeffModel); 

If I fit a sub-range of the distribution, in that case returned value of fraction “coeffModel” will be only in this sub-range or this will correspond to full range fraction?

If this fraction corresponds to sub-range, how I can translate this into corresponding value of fraction in full range?

If I do similar study using TFraction Fitter, evaluation of fraction by fitting sub-range i.e. fit->SetRangeX(0,rMax);
What will be the corresponding fraction value, it will be w,r.t. sub-range events or full range?

Many thanks for your feedback!