The Battle of Junin was an all-cavalry action without any gunfire (only lances and swords). But I will list all the troops.

Peruvians
2nd. Battalion of the Legion
1st. Battalion of the Guard
3rd. Battalion of Peru
3rd. Battalion of Trujillo
3rd. Battalion of Cmdt. Vallari
Infantry Regiment Civicos
Infantry Regiment Tiradores of the Guard
Infantry Regiment Rifles
Cavalry Regiment Coraceros (3 Squadrons)
3 Squadrons Hussars of the Guard
Hussars of Riva Agüero
Squadron of Cmdt. Mancebo
Squadron Lancers de la Victoria
Squadron Hussars of Peru
Squadron Lancers of Peru
Peruvian Division Commander: Grand Marshal José de la Mar
2 Brigades of Artillery
Infantry Battalion Legion Peruana

Argentine
Infantry Battalion No 1
Infantry Regiment Rio de la Plata
Infantry Battalion No 2
Infantry Battalion No 11
Infantry Battalion No 5
Cavalry Division, Commander: General Mariano Necochea
Cavalry Regiment Granaderos Caballo

Gran Colombia
Regiment, Grenadiers of Colombia
Infantry Battalion Rifles (2 Squadrons)
Infantry Battalion Vencedor Hussars of Colombia (3 Squadrons)
Infantry Battalion Voltigeros Hussars of Peru (3 Squadrons)
Infantry Battalion Pichincha Squadron, Grenadiers of the Andes
Infantry Battalion Bogota
Infantry Battalion Vargas
Cavalry Regiment Hussars
Artillery Peruvian
Commander: Major Fuentes
6 Field Pieces

Royalists
Division of General Rafael Maroto
1st. Infantry Battalion Infante
1st. Infantry Battalion Imperial
1st. Infantry Battalion Burgos
1st. Infantry Battalion Cantabria
Division of General Juan Antonio Monet
2nd. Infantry Battalion del Primer Regimiento
2nd. Infantry Battalion Victoria
2nd. Infantry Battalion Guias
2nd. Infantry Battalion Centro
2nd. Infantry Battalion Castro
Cavalry Division of General R. Gomez de Bedoya
Regiment Dragoons of the Union
Squadron Hussars of Fernando VII
Squadron Dragoons of Peru
Artillery x 9 Field Pieces

Patriots
1st. Division (Colombian)
Commander: General Jacinto Lara
Infantry Battalion Vargas
Infantry Battalion Vencedor
2nd. Division (Colombian)
Commander: General José M. Córdova
Infantry Battalion Bogota
Infantry Battalion Voltigeros
Infantry Battalion Pichincha
Infantry Battalion Caracas

Extract from Gen. Miller on the Battle