All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
Turning to Allah with sincere repentance is possible at any time since He has promised the repentant mercy and forgiveness as mentioned in the following verse where He Said (What means): "O ye who believe! Turn to God with sincere repentance: In the hope that your Lord will remove from you your ills and admit you to Gardens beneath which Rivers flow,- the Day that God will not permit to be humiliated the Prophet and those who believe with him. Their Light will run forward before them and by their right hands, while they say, "Our Lord! Perfect our Light for us, and grant us Forgiveness: for Thou hast power over all things." [At-Tahrim/8].
There is no doubt that one of the conditions of sincere repentance is to return others' rights in order to avoid punishment in the Hereafter. In this regard, the Prophet (PBUH) said (What means): "Whoever has oppressed another person concerning his reputation or anything else, he should beg him to forgive him before the Day of Resurrection when there will be no money (to compensate for wrong deeds), but if he has good deeds, those good deeds will be taken from him according to his oppression which he has done, and if he has no good deeds, the sins of the oppressed person will be loaded on him." [Al-Bukhary/pp.2449].
In conclusion, if you (Questioner) were able to return the stolen money without notifying your father to avoid making him angry, then this would be your priority even if you had to borrow it from your brothers or anyone else. But, if you couldn't then you should tell your father the truth and ask him to pardon you. And Allah Knows Best.