Dear Niraj, NDA Medicl test requires a Candidate to:

• Be in good physical and mental health without any disease that might interfere with his duties
• No evidence of bodily defects or under weight
• And no weak constitution

Now a surgery is a medical necessity, If it does not interfere with your daily activities or doesn't cause you to be ill, this should not be any problem. We are guessing it might be appendicitis and that is not a problem.