Hi @vijay01996 -
There are several global soil datasets that provide soil depth. The one we probably use most often is ISRIC Soil Grids. The InVEST User Guide for this model has an Appendix that lists some global sources of data for each input.
As far as I know, there is no already-prepared global dataset for PAWC, this is something that we need to create manually using other soil data, like you would get from ISRIC or the Harmonized World Soil Database. Years ago, when we were still using HWSD, I made a simple document outlining how to process the HWSD data into soil depth and PAWC - it might still be useful as a guide for preparing data from other soil databases.
~ Stacie