Assalamualikum sheikh, I heard a person gets reward of praying the whole night if he finishes taraweeh with the imam, but my question is how can one achieve that reward while also being able to pray in the last third of night? As imam conclusion with witr, so what i do for the 1/3 of the night?

Ustadh AbdulAziz al-Haqqan

Pray with the imam and finish with him to fulfill the hadeeth in sha'a Allah. And if u want to pray later that is not a problem.