If the Adhan for Fajr is given while you are praying Witr, you should complete your prayer and there is nothing wrong with that.

Can a Muslim use his father's money for Hajj? Islam permits a Muslim to use his father's money for Hajj. It is not a requirement that Hajj be performed with one’s own funds. If the father has already completed his own Hajj, it is commendable and rewarding for him to help his child perform theirs.

There is nothing wrong in offering some Nafl (supererogatory) prayers in congregation, but this should not be a regular habit such that every regular Sunnah prayer is offered in congregation, because that is not prescribed.

The two Sunnah Rak`ahs of Fajr are to be offered after the Adhan for Subh and before the obligatory prayer. They are called Sunnah of Fajr or the Sunnah of Subh and they are among the twelve regular Sunnahs.

The time for Witr prayer ends when dawn comes. However, it was narrated from a number of the Companions that there is nothing wrong with praying Witr after the Adhan of Fajr until the Iqamah is given.

Witr is part of the night prayer, and it is Sunnah and it is the end of the night prayer, one Rak`ah with which one concludes the night prayers at the end, or in the middle, or at the beginning of the night after `Isha.

Du’a al-Qunut is recited in the last rak’ah of Witr prayer, after bowing. The formula of Du’a al-qunut was narrated by Abu Dawud, al-Tirmidhi, and al-Nasai.

It is permissible to pray Witr 3 rak’ahs with one salam, but it should be with only one tashahhud and not two, because if he does it with two tashahhuds, it will be like Maghrib prayer and the Prophet (peace and blessings be upon him) forbade making witr like Maghrib prayer.