nope... unless someone made a mod to load json from mod folder.
example. i made 4_ModGraphicsPath.rb.DIS to load graphics from outside to prove this logic can be real.
if u want it work, rename it to "4_ModGraphicsPath.rb" and RGSS will load modscript\graphics\ b4 load image files from graphics\
if u want load json data from modscript/ u have to make ur own mod.