Jesus knew. And it is recorded in Scripture that He knew. He called Judas unclean. He called him the son of perdition. That means Judas was doomed to destruction. If you believe Judas was saved at one time, then he lost his salvation, whereas Jesus says He will lose none of those who are given to Him.
John 6:64 "But there are some of you who do not believe.” For Jesus knew from the beginning who they were who did not believe, and who it was that would betray Him.
Yes..n it said many desciples chose not to follow after that but the 12 remained (refering to john 13)..
But like truthtalk? Said ..you cant betray someone you were never "in" to begin with..