How should one address the situation legally if a medical report indic

My wife and her parent are saying boy is impotent but we have physical relation and she leaves me within 15 days. I went for the medical test in my medical report there impotency came. Now she is demanding huge amount which is impossible for me to give. We did not take any dowry. We have decided that we will give food expense of our relative yourself and I have paid to her parents. If I agree in the court what will happen.