Is it possible to have multiple themes on single domain? if it is possible, from where we can get these type of themes?
Yes, you can add multiple themes in your Shopify store, But at a time you can publish only one theme, so you have to maintain all the themes you will add. so that you can do live any time you want.
It’s possible and I will provide the theme for you if you want I have more than 15 shopify themes.