When does bitcoin wallet subtracts the coins spent by that particular address? After how many confirmations does the bitcoin wallet subtracts/updates the account balance in respect of respective wallet address.
Bitcoin Core does not have a concept of address balances.

It has a concept of a wallet balance. The wallet balance is the sum of the values of all the transaction outputs that are:


Not serving as input to any (confirmed or unconfirmed) transactions that are not abandoned.
Either:


Confirmed (at least one confirmation)
Unconfirmed, but produced by a transaction that we signed ourselves ("change").