I wonder if you ask similar questions about Muslim & Christian faith & their religious stories. Well, I agree Hanuman may've never taken a round trip from Sri Lanka to Himalaya & Ravan may not have had 10 heads, but there's no proof that they didn't exist. Does ASI (Archeological Society of India) have any proof of existence of Mohammed or Jesus? The reason why we have no proof is because we haven't looked for it hard enough. Ofcourse, all such findings need heavy support (both finance & infrastructure) from science (ehich starts with a positive mindframe abt this).