RSE or ISE — which one should I actually take?

The cleanest way to decide is one question: who will be on the other side of your conversations? If it's a person — someone with an RRSP, a retirement date, a risk profile, and feelings about market drops — that's the retail path, and you want the RSE. If it's an institution — a pension fund with a liability schedule, a hedge fund needing prime brokerage, a corporate treasury moving size — that's the institutional path, and you want the ISE.

They're parallel tracks after the CIRE, not a sequence: you don't need both, there's no order between them, and neither is a stepping stone to the other. In most cases this isn't even your decision — your sponsoring dealer registers you in a category and the category dictates the exam, so if you're hired onto a retail advisory team the question is already answered.

Since you're choosing a direction rather than decoding an offer, look at what each exam tests: the RSE is a client-judgment exam (KYC, suitability, recommendations), the ISE is an analysis-concentration exam — securities analysis is 31% of it alone. Whichever one you'd rather be tested on for a living is real career information.