If you pray the Tarawih with the Imam (the one who leads congregational Prayer), it is preferable to perform the Witr with him in order to get the complete reward. The Prophet (peace be upon him) said:
"If one prays with the Imam until the Imam ends, it is regarded as having spent a whole night in prayer.''
Abu Dawud and
Al-Tirmidhy. If you woke up during the night and wanted to offer optional Salah (Prayer), you can offer whatever you want without offering Witr, for it is not permissible to offer two Witrs during one night. However, If you left the Witr till the end of night, there is no problem.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.