Performing the Tahajjud prayer in congregation in the last ten days of Ramadan is permissible
13-1-2014 | IslamWeb
Question:
What is the religious ruling on performing the Tahajjud prayer in congregation in the last ten days of Ramadhaan?
Answer:
All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
Performing the Tahajjud prayer (i.e. the optional night prayer performed after waking up from sleep) in congregation in the last ten days of Ramadan in the mosque is permissible according to the consensus of scholars. The prophet performed the Tahajjud prayer in congregation in the last ten days of Ramadan in the mosque as was reported by Imaam Al-Bukhari, Muslim, Ahmad and others 
. The difference of opinion among the scholars lies in whether it is recommended to perform the Tahajjud prayer individually in homes or in congregation in the mosques. We believe that it is left to the individual to decide what suits him, is the optimal choice for him in terms of attaining Khushoo‘ (i.e. observing the prayer humbly with an attentive and submissive heart) and guarantees observing Ikhlaas (i.e. the devotion of one's intentions and acts solely and sincerely to Allaah The Exalted). If one believes that performing the Tahajjud prayer in congregation in the mosque is better for him in terms of attaining Khushoo‘ and observing Ikhlaas, then it is recommended for him to perform it in congregation in such a case instead of individually.
The prophet used to perform the Tahajjud prayer in congregation in the mosque in the last ten days of Ramadan. Abu Tharr 
said, "We fasted with the Messenger of Allaah in Ramadan and he did not lead us in Qiyaam (i.e. night worship) until there were seven days left in the month. Then he led us praying Qiyaam when there were five days left until one-half of the night had passed. We said: 'O Messenger of Allaah! What if we spend the rest of this night praying individually?' He said: 'Whoever prays Qiyaam with the Imaam until he finishes, Allaah The Exalted Will Record for him the Qiyaam of a (whole) night.' After that, he did not lead us in prayer until there were three days of the month left. Then he led us in praying Qiyaam when there were three days left. He gathered his family and wives (and led us in prayer) until we feared that we would miss Al-Falah. I (one of the narrators) said: 'What is Al-Falah?' He said: 'The Suhoor (i.e. pre-dawn meal).'" [Abu Daawood, At-Tirmithi: Saheeh; An-Nisaa'i, Ibn Maajah and others: with a good chain of narrators]
Allaah Knows best.