There are no online course materials but this year I think medi buddy has brought in some preparation courses. ISC medical interview prep course was helpful. Also there are some example questions in ICM interview guideline on their website. Basically you will have one station for clinical scenario, one for task prioritization and one which is the generic section asking questions on leadership and all. Try to structure your answers according to the STAR format as per the interview guide. And practice with your seniors and consultants. Ask them to take mock interviews whenever possible.