If i have bruised ribs from a car wreck and they told me my platelet count is low and where my ribs are bruised is bleeding what can that be?

Bruise: When your platelet is significantly low and you have trauma -yes, you can have bleeding. Bleeding can happen in the skin tissue ( you see as a bruise) , or tissue underneath the skin or perhaps even on the deeper tissue- ( hematoma- accumulation of blood) depending on how significant is your trauma. Sometimes, bleeding can happen even without trauma if your platelet is very very low.

Low platelets...: Low platelet count (thrombocytopenia) can cause bleeding. Platelets normally stop blood loss by clumping and aiding in blood clotting.