1. Is sunnat also to be offered while offering qaza namaz?
2. After reading attahiyat and darood sharif rabbana atteyna also to be versed
(Questions published as received)
In the name of Allah, the Most Gracious, the Most Merciful.
1. When offering qaḍā’ ṣalāh, it is not compulsory for one to perform their sunnats unless one is making qaḍā’ of that days Fajr ṣalāh before zawāl. 
2. After one reads tashahhud (at-Taḥiyyāt) and Ṣalawāt (durūd sharīf) one may recite any du‘ā’ mentioned in the Qur’ān or narrated in the Aḥadīth/proven from sunnah. 
And Allah knows best
(Mufti) Bilal al-Mahmudi
Checked and Approved by,
Mufti Luqman Hansrot
 Tabyīn al-Ḥaqā’iq. Vol 1, Pg. 183. Imdād al-Fatāwā. Vol 1, Pg. 337. Fatāwā Dārul- ‘Ulūm Zakariyyā. Vol 2, Pg. 454.
 Marāqī al-Falāḥ Ma‘a Ḥāshiyah aṭ-Ṭaḥṭāwī.