You have to go through several rounds. First there is a one-on-one interview with lower management, a group interview with several senior financial advisors, and a one-on-one interview with the managing director. You will also have to complete a multiple-choice test which ensures you have basic math and economics knowledge. You will need to know basic economics terminology and concepts such as GDP, CPI etc. It is a general test, and doesn't require specific market knowledge.
The questions asked are typical, also dependent on the manager interviewing you. Remember that the FA job is foremost about charisma and personality. You are interviewing for a sales job -- prepare accordingly. Having a preliminary business plan (types of prospects you will pursue, market segments, etc.) prepared will be more useful than rattling off reams of stock market knowledge. It is assumed that you will learn this as you go. Remember: more sales people from non-financial industries get hired than financial industry quants.
This also goes without saying: dress accordingly. This is a white-shoe firm. Women: Wear a dark pantsuit or skirtsuit with a pressed blouse. Demure hair and make up, not too much scent. And wear heels, preferably dark leather, definitely close-toed. Men: A suit, tie, shirt, all pressed. Cufflinks and subtle cologne. Dark, shinable leather shoes. Now is not the time to stand out and make a statement.
You will also need to complete your Series 7, 66 (state), and state insurance licensing (to sell annuities) after you are hired. You basically get one shot at each test but LOTS of time to study and materials to study. Good luck.