The Camp Nou 'El Clásico' is most likely to be rearranged for the 18th December. FC Barcelona released a statement suggesting that their preferred choice would be on the 18th December and a short while later Real Madrid announced the same thing.
The original date for 'El Clasico' was the 26th October but that was postponed after widespread unrest in Barcelona.
Madrid's official statement in full was: "n light of the Real Federación Española de Fútbol's Competition Committee ruling which postpones the match scheduled to be played on Saturday 26th of October between F. C. Barcelona and Real Madrid C. F., and states the clubs must agree a new date for the fixture, Real Madrid wishes to communicate that the date proposed by both said clubs is the 18th of December."
Comunicado Oficial.#RealMadrid— Real Madrid C.F.⚽ (@realmadrid) 18 de octubre de 2019
LaLiga will present this plan to the Competition Committee before it's made official.