If taking a daily of maltofer (iron) for a month raised my hemoglobin from 9.5 to 10.3, can I say anemia is due to low iron. Platelets normal, WBC too?

Possibly. Before taking any medication or dietary supplements it is very important to know the exact type of anemia and its cause. Iron deficiency is one of the main causes but there are others: vitamin b12/folate deficiency, chronic disease, genetic conditions, certain medications, toxins, etc. Consulting a hematologist is recommended.
Anaemia. A haemoglobin of 9.5 is low. If you took an iron containing supplement and your haemoglobin went up to 10.3 it is very possible you were iron-deficient. But you need to get this investigated, especially if you are consuming an otherwise healthy diet. The underlying reason for the anaemia needs to be determined.