  The work deals with universal thermodynamics for flat FRW model, considering
interacting $n-$fluid system. By introducing the state finder parameters, the
feasible regions in the $\{r,s\}-$plane has been examined for the validity of
the Generalized Second Law of Thermodynamics. A general prescription for the
evolution of the horizon has been derived for general non-static spherically
symmetric space time and then it is applied to FRW universe. A general
restriction on the matter has been found for the validity of GSLT.
