Thank all for the help (guidance) . After connecting the raspberry to the HDD I have found the WALLET.dat , it was hidden in the folder
WALLET ID.
Have you imported the wallet.dat into bitcoin core?
Is there a passphrase?
Do you have it?
You don't need to download the whole blockchain to check.
Download bitcoin core software
On the debug console, run
listaddressgroupings
or
getaddressesbyaccount ""
to get a list of addresses controlled by the wallet
Check the balances of the address on any block explorer.
If you want to export the private key of any address into an SPV wallet like Electrum
Unlock the wallet (if it is encrypted with a passphrase)
walletpassphrase 1000
Then use dumpprivkey to dump the private key of the address
Eg
dumpprivkey 1YourBitcoinAddress
This will bring up a string of alphanumeric characters starting with either 5, K, or L
That's your private key, that's how you can spend bitcoins, if you share it with someone else then they can spend your bitcoin, if you lose it then you'll most likely lose your bitcoins forever.
You said
He has I need to decrypt the same
Which makes me doubt you have the passphrase for the wallet.dat in the first place.