Judas knew exactly what he was doing in betraying Jesus. He even negotiated payment with the priests. John tells us exactly what kind of person Judas was - he was a hypocrite and a thief.
John12:4-6 But Judas Iscariot, the disciple who would soon betray Him, said, 5 "That perfume was worth a year's wages. It should have been sold and the money given to the poor." 6 Not that he cared for the poor—he was a thief, and since he was in charge of the disciples' money, he often stole some for himself.
Any attribution to Judas of noble motives in his betrayal are speculative and contradictory to scripture. Jesus himself says that Judas was lost and calls him "the son of perdition."
John 17:12 While I was with them in the world, I kept them in thy name: those that thou gavest me I have kept, and none of them is lost, but the son of perdition; that the scripture might be fulfilled.
The word for "perdition" used by Jesus about Judas is απώλεια, apōleia, and it means destruction or utter ruin especially that brought about by the judgements of God.
Judas was an evil man who did not understand his Lord at all. Judas committed suicide and did not seek forgiveness. Why? Because he completely failed to understand the work of the Lord Jesus Christ and the merciful kindness of our Heavenly Father.
Make no mistake. Judas is lost. The Lord himself says so. The world tries to make excuses for Judas because he reminds them of themselves. As followers of Christ, let's not fall into that trap. Rather, we should learn the lesson of Judas that betrayal of our Lord and saviour carries with it a terrible weight of judgement. However, even in the worst case of sinfulness there is forgivenes in Christ for those who, unlike Judas, seek that forgiveness in sincerity and true repentance.
Judas was definitely not forgiven. He will be raised to judgement when the Lord returns and will see, before he suffers the second death, what glory he traded for 30 pieces of silver.
Matthew 27:3,4 Then Judas, which had betrayed him, when he saw that he was condemned, repented himself, and brought again the thirty pieces of silver to the chief priests and elders, saying, I have sinned in that I have betrayed the innocent blood. And they said, What is that to us? see thou to that. And throwing down the pieces of silver in the temple, he departed; and he went and hanged himself.
I hope you have found this helpful.