There is nothing called Hinduism before Arabs invented the word. So, during King Ram's (in case he existed) rule, he was a follower of Vedas. Sivaism is religion practiced in South. There are no scriptures that that mention about Ram in Sivaism scriptures. Siva is the only superior god in Sivaism. Like that, East India has their own scripts. Ram is the God for Vaishnavaites who are the majority in Northern India and Central India. And the Lord Ram existed in scriptures thousands of years before Ramayan came to picture.
