You mean you need to find parameters where the steady state can be found?
First off, you need to find out whether the steady state for a particular parameter set exists as opposed to Dynare not being able to find it. If the latter is the problem, just changing the parameters is not advocated. Rather, you should try to analytically compute the steady state.
If the former is the problem and you want to know whether the steady state could be found, follow my code at [Loop over parameters)
There, you loop over stoch_simul, which returns the variable info. This one stores the error codes. If info is 20, 21, or 22 the steady state was not found, was complex, or contained Inf/Nan, respectively.