it will never going to happen such a thing because bitcoin is decentralised and ripple is centralised coin so there is no such a chance or something and they are not same in no aspect ..
No coin can replace the BTC, at present BTC prices are at $ 6400, and RIpple is at $ 0.46, do not understand why the questioner can predict two coins I have never thought that the ripple would be a coin to replace the BTC in the future.