http://www.trucounsel.com/index.php/v-depositions-and-discovery/rule-26-general-provisions-governing-discovery#text will give you the basic rules of dicovery. Then you could try googling NRCP 26 and protective order to see if any cases pop up. Discovery issues are seldom the subject of Nevada Supreme Court Opinions. You could also look throught the Discovery Commissioner Opionions found on the Nevada Bar Website. http://www.nvbar.org/content/southern-nevada-discovery-commissioners-opinions and http://www.wcbar.org/publications.html.
You can go to the law library andhave the librarian help you search the Nevada Statutes and Nevada Supreme Court opinions. You won't find much of anything specific to discovery in paternity cases, as true discovery is rarely done in such cases, and if what you need is specific to that subject you may need to branch out to other states. Protective orders are very rarely granted in any type of case. Be aware that, in general, anything of relevance to the subject of the proceeding, whether or not admissible in court, will be discoverable.
Responses are for general information purposes only, and are based on the extremely limited facts given. A consultation with an attorney experienced in the area of law(s) indicated in the question is highly recommended. Information and advice given here should not be relied upon for any final action or decision, as the information is limited by its nature to the question asked and the fact(s) presented in that question. THIS RESPONSE DOES NOT CREATE AN ATTORNEY/CLIENT RELATIONSHIP, particularly considering that the names of the parties are unknown.
The UNLV Boyd School of Law has some experienced law librarians that can assist you in finding what you need. You might even be able to get a student to help, though that's a bit dicey as some students may not know much more than you how to research. Another option would be to try Google Scholar. It's more of a shotgun approach, but you can often find relevant cases and articles. Of coure, you could also hire an experienced attorney who probably already knows what you need.