Hi,
How much time it requires to deposit from credit card to btc exchangers like kraken or other similar exchangers?
How fast from bank account?
As stated by the post above me, you can buy BTC from Cex.io if you'll gonna use credit card to buy it. I personally bought some BTC from Cex.io and the transaction is really fast. I can say that it is instant. Just be mindful of the fees that you must pay when using the said site. And after getting your
BTC from Cex.io, you can then transfer it to any wallet or exchange in the internet. The duration of transaction for it to be confirmed depends on the amount of fee you paid.
As for banks to exchanges, it should take 3 business days to 1 week for them to process your deposit.