Based upon what I can find regarding the Yugoslav Navy and its procurement history, the following represents the best estimate I have of its status.
Detailed Summary of the Royal Yugoslav Navy, December 1937
Type Class Quantity Ships
Coast Defense Ship Kornilov 1 Kornilov
Light Cruiser Saida 1 Orao
Light Cruiser Ceres 1 Hrvatska (ex Curlew)
Destroyers D-13 2 Dubrovnik, Beograd
Destroyers 15 6 Bespokorny, Derzki, Gnenny, Pospihny, Pylki, Tserigo
Destroyers Tatra 4 Durmitor, Kaimakcalan, Suvobor, Cetnik
Torpedo Boat Skopje 4 Skopje, Novi Sad, Sarajevo, Bitola
Torpedo Boat Orjen 3 Orjen, Velebit, Dinara
Frigates F-1 2 Zagreb, Ljubljana
Armoured Gunboats Vardar 2 Vardar (former Gunboat A), Morava (former Gunboat B) - on trials
Minecraft 5 Galeb, Jastreb, Sokol, Kobac, Labud
Submarines Type I 3 S-1, S-2, S-3
Submarines Afrika 6 O-31 (ex I-10), O-32 (ex I-11), O-33 (ex I-12), O-34 (ex I-13), O-35 (ex I-14), O-36 (ex I-15)
Motor Torpedo Boats MTB-82 10 MTB.1 through MTB.10
Coastal Motor Boats Type 1 50 CMB.1 through CMB.50
River Monitors Drava 2 Karageorgevich (ex Drava), Obrenovich (ex Morava)
Order of Battle of the Royal Yugoslav Navy, December 1937
Note: W(X) + Y(Z) = completed (under repair/refit) + under construction (- scrapping vessel)
CDBB 1 (0) + 0 (0)
CL 2 (0) + 0 (0)
DD 12 (0) + 0 (0)
TB 7 (0) + 0 (0)
FS 2 (0) + 0 (0)
PG(A) 2 (0) + 2 (0)
MC 5 (0) + 0 (0)
SS 9 (0) + 0 (0)
MTB 10 (0) + 0 (0)
CMB 50 (0) + 0 (0)
MN(R) 2 (0) + 0 (0)