Dated centuries before the advent of Platoan and Christian doctrines
Apophatic theology is the idea of interpretation of God through the process of eliminating everything God is not. An apophatic approach is today utilized even in areas like mathematics wherein a geometric theorem tries to define the properties of an object by eliminating simple features of what it is not.
For a human brain to understand something abstract and complex in nature, it needs some parameters (that the human brain is familiar with) to relate to it and understand it as an analogy. A similar understanding process is the apophatic approach where you try to base your understanding on what something is not, and somehow through that, you understand what it exactly is.
From a philosophical perspective, the understanding is quite subjective, meaning, everyone has their own interpretation of a concept, but the way they may explain it might not resonate with others. This is due to the limitation of using Words or Vāk.
It is commonly believed that Apophatic theology originates from “Plato and some Early Christian writers”. While it is good to recognize the presence of apophatic approach in different cultures and timelines, it is also important to recognize one of its early appearances in renowned texts like the Vedas.