I used to think that the similarity of words pilaf and Hindi Pulao is because of a recent exchange of recipes from the East. But apparently rice was grown in the central Asia when it was imported from South Asia in ancient times. The Muslim traders returned to South Asia what we know today as Biryani. The modern Hindi word pulao comes from Sanskrit pulaaka (which means a lump of rice, ref. A Sanskrit-English dictionary , Monier-Williams).
The word pilaf is found in Turkish, Greek, Armenian and some other Central Asian languages.