Imam Ali al-Rida
'Alī ibn Mūsā ar-Riḍā (Arabic: علي ابن موسى الرّضا), also called Abu al-Hasan, Ali al-Reza (c. 29 December 765 – 23 August 818) or in Iran (Persia) as Imam Reza (Persian: امام رضا), was a descendant of the Islamic prophet, Muhammad, and the eighth Shi'ite Imam, after his father Musa al-Kadhim, and before his son Muhammad al-Jawad.
Sheikh Mufid (r.a) and Ibn Shahr Ashoub (r.a) have only recorded one son for Imam Reza(a.s) and he is Imam Muhammad al-Taqi al-Jawad (a.s) but some other historians have recorded five sons and a daughter for him.
As for Imam Jawad (a.s) the sons are Imam Ali al-Naqi al-Hadi(a.s) and Musa al-mubarqa' who is buried in Qom( Chehel Akhtaran) and he also had a daughter named Hakimah Khatoon who is buried in Samerra,Iraq.
There ae different opinions among the scholars in this matter.
Al Haafidh Abu Na'eem sated in Hilyat Al-Awliyaa that Ima Al-Ridha had six sons and Jafar is one of them.
Mohammad Ibn Talha al-Shafi'ee had the same opinion.
Many of our scholars including Shaikh Al-Mufeed and Al-Erbily narrated from Imam Radha (AS) that he wl have only one son (Imam Al-Jawad) and Allah (SWT) will grant this one son lot of sons.