Please do not send ETC to ETH and vice versa, as they are two separate currencies/protocols.
If you have mistakenly sent ETC to an ETH address in Jaxx, please find your ETC private key first by going to Menu -> Tools -> Display Private Keys -> Display Ethereum Classic Keys. Import your private key into MyEtherWallet.com or similar service to split your Ether as you are unable to do so in Jaxx. Please review this article for further instructions.
If you have sent ETH to an ETC address, visit MyEtherWallet.com and create an account with your ETC private keys. The ETH, which have been wrongly sent to your ETC address, should appear. From there, you may send your ETH back to your ETH wallet in Jaxx.
Please ensure that you are sending to the correct currency in the future.