how can i send back or to send this amount of BTC if it get mixed with other BTC from my wallet ?
Do you mean "
your address" instead of "
wallet"?
Use "
coin-control"
to spend that output specifically, then send it to somewhere or back to the address in the input, spend the other UTXO (
more info) to spend that output specifically, then send it to somewhere or back to the address in the input, spend the other UTXO (
Unspent Transaction Output) on your other transactions as well.
But sending that away will not get rid of its link to the other UTXOs associated with that address,
The heuristics that link addresses or transactions together would still consider that address as one of the recipient of whatever that transaction is for,
All UTXOs associated with that address is obviously considered to be owned by its user (
you).
The best solution to that is to simply do not reuse that address anymore and use another address of your wallet.
If your wallet only issue a single Bitcoin address; consider switching to another with better level of privacy.
Then only use your address once if possible.
But if you actually mean "
wallet": It'll not be linked to your other addresses as long as you don't spend it together with your other UTXO.
Use coin-control to solely spend it and get rid of it.
(steps differ per wallet but you didn't specify the wallet that you're using)