What’s kind of authentication flow are you using? Normally, we use the Authorization Code Grant Flow that the user delegates access to a web application. In this scenario, to enables the users on other tenants to login the website and access their Office 365 resource, we only need to enable the multiple-tenant app on the Azure portal.
but if i want to access the tenant using the same application but in different azure subscription whats the way.
It depends on which REST you were using. It is same as we are call the REST API for the single tenant app if we are using the Microsoft Graph to query the OneDrive for business. The endpoint of the list children of a driveItem is still like below no matter which tenant the user login:
GET https://graph.microsoft.com/v1.0/me/drive/root/children
GET https://graph.microsoft.com/v1.0/me/drive/items/{item-id}/children
GET https://graph.microsoft.com/v1.0/me/drive/root:/{item-path}:/children
If you were using the Office 365 REST API, we need to discover the service endpoint. You can refer to here for more detail about Office 365 Discovery Service REST API.