What are the signs of someone who has renal failure be close to die?

Oh dear..... Renal failure is a complicated topic, as the kidneys impact so many aspects of our body's health. I don't know from your question if you are asking about someone else - like maybe a parent, or if you are asking about yourself. Also, is the individual on dialysis? Heart failure is extremely common in people with kidney shutdown. Please talk to the nephrologist involved to get specific answers.
Electrolyte abnormal. Severe hyperkalemia, acidosis, uremic signs like pericardial effusion, asterexis mental status changes and volume overload occur if not treated and precede terminal disease.