hitbtc, poloniex & few others can let you acquire some... they'll require you to have btc or some other crypto... you can't use fiat currency in those exchanges unless they have changed the rule.

You can also look at coinmarketcap site -> https://coinmarketcap.com/currencies/bytecoin-bcn/

Once you go to the site, click on "Markets". That markets link will take you to all exchanges that let you buy this.