hey spikedman! thanks for the reply, well usually when a coin is forked the developer will inform everyone via bitcointalk forum and social media, to claim rewards from a fork, you will need to have some of the existing coin that is going to be forked and be holding that coin in a wallet that you have access to private keys( most exchanges don't count), once that Is done anyone holding the coins in a wallet with access to private keys with get coins from the fork, usually at a 1:1 ratio..

so say if bitcoin forked and you held one bitcoin youd get one new coin from the fork for free
hope this helped!