Creatinine level is 12.6. Can this be brought down? Can it be a case of acute renal failure and things get back to normal after some treatment?

ELEV. CREAT. It depends on the diagnosis, cause and timeframe of the issues.
High creatinine. A creatinine level of 12.6 is clearly elevated. To answer your question, more history is needed. Were you diagnosed with 'acute kidney failure". If so, were you in the hospital and told what caused it? You also need to have a renal ultrasound to see if your ureters are blocked. If you are a man , see a urologist to see if you have severe prostate obstruction. You may aslo have esrd.