My brother is affected by appendices. is about 7mm width and 3mm thickness. is there is any serious about it? it need any operation?

Needs surgery: Acute appendix infection is called acute appendicitis. If that is the case, it always needs surgery.

Appendicitis?: Is a surgical emergency and brother should be evaluated by a surgeon ASAP

Appendicitis-surgery: Your question states that your brother has appendicitis, so he has been diagnosed already based on his symptoms, physical examination and lab test results. He should have surgery. Its not clear from your question about the dimensions of his appendix, but that information alone is not enough to diagnose appendicitis.