Rom 11:26 says “All Israel will be saved….” Does that mean all Israel will be given the opportunity to receive Jesus?
According to Zechariah 12:10, sometime during the Great Tribulation the Lord will pour out His Spirit of grace and supplication causing the eyes of the Jewish people to be opened to the realization that Jesus has been their Messiah all along. In Romans 11:25-27 Paul confirmed that this will happen after the Church is gone. So yes, all living Jews will have the opportunity to receive Jesus as their savior.
But I don’t think the phrase “all Israel” necessarily means every single Jew will be saved. It means that representatives from all the tribes that make up the nation of Israel will accept the Lord’s offer of pardon for their sins. At the outset of the Millennium, the promised Land will be re-distributed among the tribes of Israel and all of them will receive an allotment (Ezekiel 48:1-29). Since only believers in Jesus will be invited into the Millennium, this confirms that representatives of all the tribes of Israel will have accepted Jesus as their Messiah during Daniel’s70th Week.