Is it permissible to pray Sunnah prayers in congregation to receive the reward of congregational prayer?

Voluntary prayers (Nawafil) are permissible in congregation and individually. Praying individually is better, based on the Prophet's (PBUH) saying: "Perform prayers in your homes, for the best of a man's prayers is in his home, except for the obligatory prayers." What the Prophet (PBUH) did, performing voluntary prayers in congregation at the house of Anas's grandmother, was interpreted by scholars as being for the purpose of teaching them, not because congregational prayer is better for voluntary prayers. The preference for performing voluntary prayers individually applies where there is no benefit such as teaching.