How it will workout? If a website is using adsense currently then can I separate account can be applied?
You can apply for Adsense, BUT (and a very big BUT) there is no gurantee that you will be approved. Adsense is technically "full". They have no need for more sites/accounts as the number of people willing to pay for adverts is not growing and may even be declining due to competition from AI and other platforms for advertisers - they just do not have the inventory of adverts to supply every one who wants an Adsense account. Most new applications for Adsense (maybe as many as 95%) are not approved. To get approved these days, sites really need to provide exceptional commercial value to advertisers and the standards by which sites got approved in the past a very significantly higher today.