I would speak to the recruiting team to check exactly what the interview will involve. Accenture Strategy do use the ‘Potentia’ interview, which is an hour long interview where you're given a short paragraph of text about a broad business topic. You will then have 5 minutes to analyse the text and the question it raises.
After this, you will need to present your initial thoughts to your interviewer and they will then follow up with a series of questions. Its main objective is to test your creativity and it therefore won't involve any calculations.
Otherwise the interview will be case and fit. The case interview for Accenture is generally candidate led, like Bain and BCG; and the FIT is very similar to the other firms.
On what level - I recommend speaking with the recruiting team. It's hard to advise without seeing your resume in full.
Hope that helps!