From a record (could be any object e.g. Opportunity or any custom object), we need to able to generate the document, without having to select the document template. We will call this functionality from our VF page).
@Ruchi2 I have a couple of follow-up questions.
Will you be in Classic or Lightning?
Will users be waiting for the document to take action?
Here is some general guidance on deployments.
Option 1: Redirect to our url run page. Here is an overview video on how to construct the URL and here is the documentation for all the button parameters. You are going to want to not only define the package and delivery option but also set the Auto Run to true.
Option 2: Embed visualforce page component into your page. This allows you to really customize and control the experience. Documentation and Sample Code.