John 10:16 And other sheep I have which are not of this fold; them also I must bring, and they will hear My voice; and there will be one flock and one shepherd.
The "other sheep" are the Gentiles. Jesus in his earthly ministry was sent to the lost sheep of the house of Israel. (Matt. 15:24). It was prophesied, however, "He shall bring forth judgment to the Gentiles" (Isa. 42:1), and that he would be given as "light to the Gentiles". (Isa. 42:6 R.S.V. cf. Matt. 12:18-21). The Gentiles heard the voice of the Shepherd through the labours of the Apostle Paul, a man especially chosen for this work. (Acts 9:15; 1 Tim. 2:7 cf. Acts 18:6). The only two communities of believers ["folds" if you like] mentioned in the New Testament are the Jews and the Gentiles. As Paul puts it in Romans 1:16 "I am not ashamed of the gospel, because it is the power of God for the salvation of everyone who believes: first for the Jew, then for the Gentile." [NIV].
I hope you have found this helpful.