So, is it still possible to claim BCH? I am currently using an online wallet (BitGo) which didn't support the fork. Will I have the ability to claim my BCH by moving my BTC on an offline wallet where I can export the private keys?
How does BitGo define "didn't support the fork".
Does BitGo allow you to own your private keys? If "yes", you definitely have BCH and you just need to claim it...see the guide that someone else posted. If "no", you need to find out if BitGo was going to earmark BCH for you (in an amount equal to your BTC balance). Coinbase didn't do this, however other exchange wallets have.