If you have a Bitcoin (BTC) balance on Bittrex during the BCC UAHF time on August 1st, 5:20am (12:20pm UTC), you will be additionally credited the equivalent amount of Bitcoin Cash (BCC) on a 1:1 basis. i.e. 1 BTC on Bittrex held during the on-exchange snapshot will get you 1 BCC. Full details below.

https://support.bittrex.com/hc/en-us/articles/115000808991-Statement-on-Bitcoin-Cash-BCC-