The order of battle was:
4TH INFANTRY DIVISION/MILITARY REGION (Mourão Filho)
Tiradentes Detachment (Muricy)
3rd Company of Fuziliers (reinforced) (Cpt Mandarino)
10th Infantry Regiment (x1 battalion - a company)
11th Infantry Regiment (x1 battalion) (Col Ferraro)
2nd Battalion of the 12th Infantry Regiment
2nd Police Battalion
5th Police Battalion
9th Police Battalion (reassigned to the capital)
1st Group of the 4th Howitzer Regiment
4th Mechanized Recon Squadron
4th Intendancy Company

On the other side:
Bde Gen Cunha Melo was given battlefield command and theoretically would replace Mourão Filho in his post. Some sources name what he had as the "Cunha Melo Detachment" but it's not as official. One just calls it Divisional Infantry 1 which was his post but doesn't cover all that he now commanded nor was a frontline command.
1st echelon
1st Caçadores Battalion (Ltc Kerensky)
2nd echelon
1st Infantry Regiment "Sampaio" (several sources say 2 battalions, but one trustworthy mentions a battalion left in quarters) (Col Raimundo, also leading the whole echelon)
2nd Group of the 1st Howitzer Regiment "Floriano" (Ltc Raimundo Nonato)
3rd echelon (Cunha Melo personally present)
2nd Infantry Regiment "Avaí" (x2 battalions)
1st Group of the 1st Howitzer Regiment 
Company of the 1st Engineering Regiment (Cpt Mendonça)
3rd Infantry Regiment "Ararigboia", further behind (2nd Battalion mentioned, other probably also moved)

I've got more names, those given have some role.