Taraweeh is another important feature of Ramadan Kareem. It is a special prayer which has 20rak’at and performed right after Isha prayer. This prayer is Sunnah Maukkaddah and one should not miss it. Holy Prophet PBUH said:
"Allah has made fasting in Ramadan obligatory, and I have made the special prayer of Ramadan (i.e. the Tarawih) a Sunnah".
Offering tarawweh in congregation is also Sunnah Maukkada’. One should always offer this prayer in Mosque. If a person is sure that the time of offering taraweeh in his nearby mosque has passed then he can offer it in his house. But he should remember that he missed the chance of achieving several virtues of offering it with Jammat in mosque.
So always try your level best to offer this special prayer which comes only once a year in mosque behind hafiz-e-Quran. Paying any type of fee to hafiz-e-Quran for this purpose is not allowed in Islam. In case no such hafiz is available then taraweeh should be led by any Imaam and he can recite whatever Surah of Quran Pak he remembers.
Usually Holy Quran is finished at 27th Ramadan in almost every mosque. In this case, taraweeh should be continued till the last day of this blessed month. One should recite different Surahs of Holy Book in these last days in Taraweeh. People who leave this special prayer after the completion of Holy Quran are not following the Sunnah correctly. Taraweeh should be offered until the last night of Ramadan.
Time of Taraweeh starts after the Isha prayer so, one cannot join the Taraweeh prayer unless he offers Isha. He must offer Isha first and then participate in Taraweeh. In case he missed some rakkats of Taraweeh then he can complete it after the witr. For example, you reached the mosque when Imaam has offered four rakkats of Taraweeh. In this case, you must offer 4 Farz of Isha prayer first and then join the congregation for Taraweeh prayer. In case you have missed 4 to 6 rakkats of Taraweeh then you must perform the witr with Imaam and then offer the four or six rakkats individually which you have missed.