Dear Arti, if your surgery was for medical necessity there should be not be any reason why you would not be eligible for the course. A medical fitness test checks your height,weight, eye sight, and for any visual or audio malfunctions. You can check the complete list of medical standards required at: www.joinindianarmy.nic.in. So there is nothing to be worried about. If you meet the general eligibility criteria, you can apply for the entrance exam.