Spectrum Table

If I want to perform Response Spectrum Analysis by using IS 1893:1984,should i have to use a CUSTOM Spectrum Table?From the code book of IS 1893:1984 page no 18 we have to give the value in custom table considering 5% of damping?

Is there any procedure to define spectrum table of Is 1893:1984 without using CUSTOM Spectrum Table?

Please calrify it....