Only 12% of properties are available to rent within Rent Supplement and Housing Assistance Payment limits, according to research carried out by the Simon Communities in Ireland.
The snapshot study of 1,150 properties in ten urban areas was carried out over three consecutive days in May.
Speaking on RTÉ's Morning Ireland, Simon spokesperson Niamh Randall said the situation was desperate.
Ms Randall said of the 138 suitable properties found in the survey, there were only nine units suitable for a single person receiving rental assistance.
There were 17 units suitable for couples, 69 units suitable for a couple with one child and 43 units for a couple with two children.
Ms Randall said: "We've got 90,000 people on the social housing list.
"We've got 3,000 people in emergency accommodation, one thousand children in emergency accommodation - where is the housing going to come from for these people?"
The organisation has called on the Government to take action to address the crisis by increasing rent supplements and introducing rent certainty measures.
Ms Randall said the group questions the decision of the Department of Social Protection not to increase rent supplement limits.
She said the limits were set in June 2013 but in March of this year the department said it would not be increased, despite an 18% increase in rental rates nationally over the same period.
Ms Randall also called for an increase in rent supplement to be coupled with rent certainty measures, which might offset some of the inflation in the market.