My wife by mistake had zyloric tablet which is for uric acid as she is 23 week pregnant...is it ok or anything to worry about?

Drug Class C. Allopurinol (Zyloric) is in FDA pregnancy drug category C. This category means that there are no high quality drug studies of the effects in humans, or that harmful effects have been shown in animal studies. Please consult your obstetrician about which medications may be taken during pregnancy, where the benefits outweigh the risks of each particular treatment.
No problem. if she only took one she should have nothing to worry about.