Input parameters identification and selection along with its range is an important task to proceed with the major experimentation in research work, especially when working with some specific methods in DOE (Design of Experiment). Few parameters have to be considered with fixed values and as variables based on the limitations or ranges of the input parameter values in non-conventional machining process. Selection of the range of values is the immediate task after selecting input parameters. There should be one procedure or evidence for selecting the better range of values in the set along with the help of literature. In this research paper, the selection of range of values of 'Pulse ON Time' is discussed. Out of the four proposed input parameters to be used in the main experimentation, three were assumed as fixed and seventeen experiments were conducted to determine the range for the fourth parameter. For different values of input parameters, MRR and SR were found. Modified TOPSIS has been applied on these observations, and then from the results, better values of Ton were found out to complete set of values which are to be utilized in DOE.