A harsh fate awaited those who had joined the Vlasov Army, a force comprising several divisions of Russian soldiers armed by Germany to fight against the Red Army. The group had been organized by General Andrei Vlasov, the hero of the Battle of Moscow, who had been captured in 1942. Vlasov and several of his chief subordinates were hanged in the Lubyanka in 1946. A picture of the executed men hanging from gallows was found in Joseph Stalin's desk after his death.
If we say that ROA was nothing but armed forces subordinated to the Vlasov’s KONR, you are right saying no ROA units were deployed in the West. The 1. ROA Div (600. Div according the German numbering) was engaged in combat in March and April 1945 in the lower Oder area; the 2. ROA Div. and 3. ROA Div. (being formed) have not even reached the frontline.
If we say that ROA was a general term often used to describe Russian volunteer formations, you are wrong. By late summer 1943 there were around 40 batallions scattered across armies, corpses and divisions from the Finnish border to the Ukraine. Since May 1943, all these units were obliged by the OKW order to wear ROA badges. On Oct 15, following a number of defections which infuriated Hitler, all these units were ordered to be moved to the West. The process was completed by late 1943. According to the OKW order, ROA batallions were to form a third or fourth batallion within a German regiment. Their operations were supervised by the newly-formed „Kommando der Freiwilligenverbande beim Oberbefehlshaber West” in Paris (gen. von Wartenberg, since June 15 gen. von Niedermeyer). These units, still with their ROA badges (have photos!) were engaged in combat in the West. In many allied memoirs from Normandy you might read how surprised the Americans were when discovering that the Germans they had just captured spoke Russian.
The SS recruited Schuma-battalions of militia/police which became often part of the Waffen-SS (15, 19, 20, 29 Divisions). The Tatar Schuma battalions (8 of them) serving in the Crimea were formed into a brigade/waffenverband after they were removed from the Crimea in 1943. There were at one stage 170 Schuma battalions but many were disbanded before they were formed into Waffen-SS divisions. Also present were Schuma-Einzeldienst which served as village/town police forces but were increasingly armed. The total for both battalions and individuals was placed at 300,000 at the end of 1942 by the head of German police Daluege, this including battalions. The Schumas were very important to the SS and helped at the front and in the rear, in Army Group North Schuma battalions serve in the frontline as early as the winter of 1941-2. Munoz details the formation of numerous regiments of Latvian, Estonian and Lithuanian police and border guards which served outside the Baltic SS divisions in 1944 and often in the frontline. Some were under the 300th Division Staff at Narva. Kaminski's Brigade was eventually taken into the Waffen-SS for a while but was 12 battalions of militia in 1943 under loose Army control (2nd Panzer Army, then 9th Army), see Munoz' volume on Kaminski (also Axis Europa) for more. There were other interesting small units part of the Abwehr like Sonderverband Bergmann, if you want to learn more read Hoffmann's works.
The actual formation of divisions boiled down to twelve plus four brigades: the 600th Infantry, 650th Infantry, both of the Vlasov ROA army, the 162nd Turkish Infantry, the 300th Division Staff of Estonians, the 1st and 2nd Cossack, the 14th Waffen-Grenadier 'Galicia' Div, the 15th and 19th Latvian SS, the 20th Estonian SS, the 29th and 30th Waffen-Grenadier Divisions (both more like brigades) plus the 599th Russian ROA Infantry Brigade and Cossack 'Plastun' Infantry Brigade, finally the Kalmyk Cavalry Corps (KKK!!!) which reached 4000 men and 4 battalions in late 1943 but sunk in strength after that. Prior to the existence of any of the above there had been the Experimental Formation Center (Versuchsverband Mitte) or RNNA which was broken up into four 600-series Ost Battalions on the order of Field Marshal von Kluge in November 1942. The numbering of those battalions is confused in several sources by historians.