Neither you nor anyone knows whether or not Judas asked for forgiveness at the end.  We do know that he returned the money he received for betraying Jesus to the high priests, stating that he had betrayed an innocent person.  They told Judas that this was his problem.  In his frustration, he threw the money on the floor, and they took the money to buy a burial field for strangers.

Probably, Judas felt that he didn't have the right another minute---so he hung himself.  We know today, that extreme depression often leads people to commit suicide.  But the Church has NEVER stated that Judas is in Hell.  Dante, the poet, put him in the lowest level of Hell along with Satan and Brutus, who betrayed Julius Caesar.  But the Church has not stated that Judas is in Hell.