Answer
(Fatwa: 1281/1091=B/1429)
To celebrate the ceremony of Bismillah by gathering family members and other people and reciting especially the last ten surahs is not proved by the Quran and Hadith, hence it should be forsaken. However saying takbeer on the end of each surah from Surah Al-Zuha to last chapter of the Quran is Sunnah. Allama Baghavi has narrated a hadith by his own source from the Holy Prophet Muhammad (PUBH) in this regard. The words quoted by you also can suffice for Sunnah. But, in Tafseer Mazhari the below words of takbeer have been quoted: لااله الا الله والله اكبر Hence, it is better to say takbeer with these words. We should follow this Sunnah during the recitation of these surahs.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband