Hi @Karthik_Shanadi ,
They are using a theme called Flex 1.0 search in google and this seems to be made by outofthesandbox https://outofthesandbox.com/products/flex-theme. There are 13 styles included and having a quick look it they might be using Wink.
They may have customized the theme a little to achieve the overall website look. Incase you need help with site build or theme tweaks you can reach out to us https://bit.ly/36CgHKQ.
Hope this helps.
Eunice here from Shopify, thanks for posting!
The theme looks similar to the Impulse theme, and the Pacific theme. Both of which are available to purchase from the Shopify Theme Store.
As @ESSuperCo mentioned, there is no way of providing a definitive answer as to which theme they have used as it could have been modified.
Have you reached out to the store owner to ask which theme it is that they're using? It wouldn't hurt to ask. It looks like you can send them a message from this page here.
Are you in the early stages of building your store, or looking to upgrade your current theme? I'd love to learn more!