Source: The Great War Society, http://www.worldwar/com/tgws/rel006.htm
4th Army [107,000 troops]
3 infantry divisions
1 cavalry division
1 infantry division in reserve
2nd Army [126,000 troops]
4 infantry divisions
1 cavalry division
2 infantry divisions in reserve
1st Army
3 infantry divisions
3 infantry divisions in reserve
3rd Army [142,000] defending
3 infantry divisions on Danube River line
3 infantry divisions in Dobrudja, at Turtukai, Silistria, Constaza
General Reserve2 infantry divisions at Bucharest
This initial lineup changed considerably after the Germans launched their counteroffensive, defeating and disorganizing Rumanian forces. After reorganization the Rumanian Army again went on the offensive - we will do a follow-up orbat for this - and was again defeated. Subsequently, the Rumanian Army focused on the defensive, and largely remained inactive for the duration of the war.