Your mythological knowledge might be pretty good. But can you tell the place where Lord Ram celebrated Diwali?
You might be thinking between, Ayodhya, Lanka and Mitila etc but you are looking in the wrong direction. As per the logics, Diwali was celebrated as a mark of Lord Krishna killing the demon Narakasura.
If you know the Dasavatar, you must be knowing that Lord Krishna was the eighth avatar and Lord Ram was the seventh avatar. Therefore Lord Rama was born before Lord Krishna and could not have celebrate Diwali.
