Ethereum Classic appeared as a result of disagreement from part of the community with the Ethereum Foundation regarding 'The DAO's' Hard Fork. Users who were against it came together to reject this measure for philosophical reasons regarding the true values of Ethereum.
It is not easy to predict the evolution of cryptocurrencies in the medium or long term future, not even in the near future, but what we can do is analyze their behavior in recent months.
The most recommended platforms to make the exchange BTC or ETH with ETC are Binance or Bittrex, since they are the ones that handle a greater volume of ETC. There are also other interesting exchanges to make the change, but they are in Korean currency. In Bittrex the Ethereum Classic / Tether pair is also active.