I am currently using Matlab 2018a while i search help for waveletscattering it shows "waveletScattering not found" . Or is it compitable only in new version i.e Matlab 2018b.
First a remark. For several years "b" versions were more limited than the "a" versions, released in the first half of each year, and containing pieces of code not confirmed then in the more "stable" (or maybe "reliable") version "b". I have always preferred "a" versions J
Then, by search of your keywords, here is a link to Mathworks: https://www.mathworks.com/help/wavelet/ref/waveletscattering.html
where they describe the waveletScattering object. It seems it is referred to wavelet toolbox and machine learning.