It isn't a confirmation call. It is just an interview call for opening.
Yes it is a offer letter,were you will be undergoing couple of procedures offer letter will be rolled off based on the company requirement
It is just a confirmation call for conducting an interview from HR prospective.
You should receive offer letter from HR
After they selected me for accenture that is with in a week
I am not sure about that . I got placed off campus as a fresher in Accenture through Amcat .
No, there will be follow up interviews. They might have picked up your resume from job boards