How can I wake up for Fajr prayer given that my brother sleeps for a long time and my family disturbs me at night?

Delaying Fajr prayer is not permissible in Islamic law under any circumstances, and it is a sign of hypocrisy, especially Fajr and Isha prayers. This is based on the Prophet's ﷺ saying: "Indeed, the heaviest prayers for the hypocrites are the Isha prayer and the Fajr prayer." One must take the necessary measures to wake up, such as sleeping early, using an alarm clock, having a sincere resolve, and supplicating to Allah Almighty for success.