They cursed those who fought Amir al-Mumineen (as)

In this article we shall see the companions of al-Redha (as) cursing those who fought Amir al-Mumineen (as), and al-Redha (as) did not only accept this but was pleased with this action, we shall begin with the Ahadith.

Sheikh al-Saduq:

35 - Narrated to us from Muhammad Ibn Yahya al-Sowlif from Oan Ibn Muhammad from Sahl Ibn al-Qasim who said al-Redha (as) heard one of his companions say: "May Allah curse those who fought Amir al-Mumineen (as)." Then al-Redha (as) told him, "Say: except for those who have repented and improved themselves." al-Redha (s) then added, "The sin of those who disobeyed him (i.e. Amir al-Mumineen) and did not accompany him to fight corruption and the corrupt ones is even greater than that of those who fought him and then repented. And God made them succeed in repenting."
35 - حدثنا محمد بن يحيى الصولي، قال: حدثنا عون بن محمد قال:
حدثنا سهل بن القاسم قال: سمع الرضا عليه السلام عن بعض أصحابه يقول: لعن الله من حارب أمير المؤمنين عليه السلام فقال له: قل إلا من تاب وأصلح ثم قال: ذنب من تخلف عنه ولم يبت أعظم من ذنب من قاتله ثم تاب.
- Uyoon Akhbar al-Redha, Vol.2, Page 94

Allamah Baqir al-Majlissi:

[Chapter Eight] Chapter on the one who fought Ali Amir al-Mumineen (as)

289 - Uyoon Akhbar al-Redha (as) : al-Hussein Ibn Ahmad al-Bayhaqi from Muhammad Ibn Yahya al-Sowli from Oan Ibn Muhammad from Sahl Ibn al-Qasim who said al-Redha (as) heard one of his companions say: "May Allah curse those who fought Amir al-Mumineen (as)." Then al-Redha (as) told him, "Say: except for those who have repented and improved themselves." al-Redha (s) then added, "The sin of those who disobeyed him (i.e. Amir al-Mumineen) and did not accompany him to fight corruption and the corrupt ones is even greater than that of those who fought him and then repented. And God made them succeed in repenting."
[الباب الثامن] باب حكم من حارب عليا أمير المؤمنين صلوات الله عليه 289 - عيون أخبار الرضا (ع): الحسين بن أحمد البيهقي عن محمد بن يحيى الصولي عن عون بن محمد عن سهل بن القاسم قال: سمع الرضا (عليه السلام) بعض أصحابه يقول: لعن الله من حارب أمير المؤمنين (عليه السلام) فقال له: قل إلا من تاب وأصلح. ثم قال له: ذنب من تخلف عنه ولم يتب أعظم من ذنب من قاتله ثم تاب.
- Bihar al-Anwar, Vol.31-32, Page 417

With those two narration in head we can conclude that Aimah (as) agreed on those words as they didn't refuse them or attack them which is commonly called Taqrir, the Aimah (as) were pleased of such act so we can do the same.

Sayyed Muhammad Baqir al-Sadr:

Indication of Taqrir: *
The silence of an infallible on a position concerning him prove his acceptance. 
دلالات التقرير:
سكوت المعصوم عن موقف يواجهه يدل على امضائه،
- Duroos Fi 'Ilm al-Usool, Vol.2, Page 113

Conclusion: al-Redha (as) did not deny this curse regarding the people who fought Amir al-Mumineen (like Aisha, Mu'awiyah etc) but he rather explained, gave his opinion regarding his companions that if one did Tawbah (i.e repentance) Allah will accepted it. Him not denying this issue and having a silence on it show his acceptance.

* See comment section for more details.