In some mosques rakahs of taraweeh prayer are 8 and in some 20. So, what are the sunnah rakahs of taraweeh (8 or 20) ?
It is up to the decision of the individual worshipper based on his school of thought called in Arabic Madhhab.
A Muslim strictly following Hanafi or Shafi school of thought would pray 20 Rakah
It is not wrong or a sin to pray 8 Rakah or increase it to 20 Rakah
these are trivialities in religion
God looks at the intentions and sincerity and God consciousness(Taqwa) of the individual not e quantity of his worship in judging His slave