A gross rental yield does not necessarily describe the money available to investors. Maintenance, management fees, property taxes, insurance, financing costs and reserves can all affect distributable income. Vacancy and delayed collections can reduce it further.
Projected returns depend on assumptions about future rent, occupancy, expenses and the eventual sale price. An IRR estimate combines the amount and timing of cash flows; changing an exit assumption can materially change the estimate. Read the downside case as carefully as the base case.
Your checklist: ask whether the yield is gross or net; identify all fees; understand the distribution policy; compare actual collections with projections where records exist. An income target is not a fixed deposit or a guarantee.