I have my BTC in paper wallet at the time of fork will i get BTC gold?
Yes, but you have to ask yourself if it's worth the trouble to compromise your cold storage (and the privacy thereof) to get this altcoin airdrop. The developer team comes off quite pathetic; they are pre-mining the chain. That's why it's not a "fork" in the sense of "update" but it's rather just a snapshot of the blockchain underlying a new altcoin.
The developers haven't been able to add replay protection successfully thus far (there is an open bounty for it with payment coming from the pre-mine), which doesn't bode well for the project. I'm guessing there will be a quick spike in price when it launches due to initial illiquidity, but long term I think project is dead in the water.
Of course it's worth it. No matter if its a premined coin it's still got a lot of exposure and will be worth something in the first few days which will be worth selling.