First, the short answer is to expect anything! So, be prepared to react professionally and calmly to any scenario.
Second, make sure to check what they mean by "role play interviews". There is a chance that you are misinterpreting and this is simply a regular case interview (which is role-playing, by the way). Double check!
Finally, if it is indeed a "roleplay" expect them to act out a client scenario. Expect the client to be angry about something, unclear on a recommendation, bring up a new issue or unexpected scenario, etc. etc. No matter what, you need to keep your cool, communicate well, and act appropriately.
My main recommendation is to hire a coach for one session! They can effectively roleplay for you as they've worked with clients and know what to expect AND how to behave.