I am unsure what he wants exactly. The M-files needed for IT2FL simulation are provided by Prof. Jerry Mendel (link is given in his previous Question thread) and Dr. Dong-rui Wu.
But I think he is probably looking for some GUI toolboxes for creating IT2FIS like the "Interval Type-2 Fuzzy Logic Toolbox" that was proprietarily developed by Dr. Juan R. Castro, Prof. Oscar Castillo and Dr. Luis G. Martínez. The "IT2FL Toolbox" does not come with standard MATLAB installation. The following image is an excerpt from the article.