"WARNING: @YobitExchange is refusing to update #NewYorkCoin wallets. Convert your NYC to ETH and withdraw it from the exchange as soon as possible. @CoinMarketCap & @coingecko have been contacted to request removal of Yobit related $NYC links from their respective #NYCoin pages."
It's highly unlikely Yobit has an NYC on either chain after the 51% attack. The old chain is easily attacked and worthless, based on comments by the mod in Yobit's troll box, Yobit does not plan to move to the updated codebase despite months of effort by the community to get them to. If you want to gamble that is up to you, but if it were me I would exit. That has been the community recommendation for weeks when confirmation of Yobit's intent was not provided.