can I give up my parental rights if I haven't had relationship with the chid and Ive been served with a summons fir paternity after 11 trs

It would almost certainly be better for you to direct this question to an Arizona practitioner -- the laws vary from place to place, and if that is where the case is, that is whre you need to seek assistance, even if you live here. That said, as explained in part in the materials posted here, you could "relinquish" your rights under Nevada law, but that would not terminate your support obligations under NV law unless someone went the extra step of filing a formal termination of parental rights action and the court elected to grant it.