My sperm count 15 million per ml and volume 3 ml and normal sperm 80% amd motilty 55% is that normal????

Not normal. A sperm count of 15 million, with 80 % normal and 55 % motility is not normal. But there is no reason to despair. While the chances of impregnating an egg are lower, it takes only one sperm to fertilize an egg and conception is determined by many more factors than the sperm count.