If what you mean to say is "I have one brother," the words in Spanish are, "Tengo un hermano." It is pronounced "TANE-go oon air-MAH-no." See the related link for audio pronunciations of many common Spanish words.
If anyone insults your family you have got a problem but there are some things that you may not know have your family done anything to the person that insulted them ? If you think no ask them talk to them and say why ?