Devatas are psychological realities (metaphysical entities). They are not physical beings. They don't have Koshas. They are aspects that manifest in our Consciousness. They are experienced within us as our vital energy rises. a typical description of God. They manifest in the state of Turiya (which is actually the substratum of all the three states that humans pass through - waking, sleeping and deep dreamless sleep state).
They are metaphors as in the legend of the tussle between Brahma and Vishnu and their sighting the pillar of fire (Shiva). Ramana Maharishi states that...
Vishnu represents the intellect and Brahma the ego, while Siva is Atma, the spirit.
Ramana Maharishi precisely captured the nature of this confusion in one such rare discussions with one of his disciples (page 375):
Later Sri Bhagavan continued: The intricate maze of philosophy of
different schools is said to clarify matters and reveal the Truth. But
in fact they create confusion where no confusion need exist. To
understand anything there must be the Self. The Self is obvious. Why
not remain as the Self? What need to explain the non-self? Take the
Vedanta for instance: They say there are fifteen kinds of prana. The
student is made to commit the names to memory and also their
functions. The air goes up and is called prana; goes down and is
called apana; operates the indriyas and is called something. Why all
this? Why do you classify, give names and enumerate the functions, and
so on? Is it not enough to know that one prana does the whole work?
The antahkarana thinks, desires, wills, reasons, etc., and each
function is attributed to one name such as mind, intellect, etc. Has
anyone seen the pranas or the antahkaranas? Have they any real
existence? They are mere conceptions. When and where will such conceptions end?
Consider the following: A
man sleeps. He says on waking that he slept. The question is asked:
‘Why does he not say in his sleep that he is sleeping?’ The answer is
given that he is sunk in the Self and cannot speak, like a man who has
dived in water to bring out something from the bottom. The diver
cannot speak under water; when he has actually recovered the articles
he comes out and speaks. Well, what is the explanation?
Being in water, water will flow into his mouth if he were to open the mouth for
speaking. Is it not simple? But the philosopher is not content with
this simple fact. He explains, saying that fire is the deity presiding
over speech; that it is inimical to water and therefore cannot
function! This is called philosophy and the learners are struggling to
learn all this! Is it not a sheer waste of time? Again the Gods are
said to preside over the limbs and senses of the individual (vyashti).
They are the limbs and senses of Virat (samashti). So they go on
explaining Hiranyagarbha, etc. Why should confusion be created and
then explained away? Ah! Fortunate is the man who does not involve
himself in this maze!