If the merger will take the form of an A-type reorganization as defined by Section 368(a)(1)(A). and the stock ownership HAS NOT (very important) of these two companies has not changed at all during the five year period ending on the date of the proposed merger ... then the NOL can be preserved
When two companies merge and one of the parties to the merger loses its corporate identity, the issue is whether various tax attributes of the distributing corporation the company that lost its corporate identity in the merger carry over to the acquiring (survivor) corporation. Section 381 controls the determination of which attributes carryover and specifies the types of transactions eligible for attribute carry-overs in the first instance.
One of the carried-over attributes specified under Section 381 is the net operating loss. Section 381(c)(1). If the transaction in question is qualified under Section 381, then the net operating loss of distributing corporation iscarried over and is subject to utilization by the acquiring corporation
Section 381(a)(2) provides that various specified types of tax-free reorganizations, including the A-type reorganization under Section 368(a)(1)(A), allow attribute carryover from the distributing corporation to the acquiring corporation
Here's an excellet resource on this: http://www.taxresourcegroup.com/library/memo/1023.html
The question about Nevada doesn't really apply here, UNLESS you re-domiciled one of the two corporations to NV ... and now you have state law (corporate law issues) but remember for 381A to hold, among other things, ownership not changing at all in the previous 5 years is a pre-requisite, and if NV requires formation rather then accepting a move-in (changing the residence/domicile) of the C corp than that would negate the no change in the previous 5 years rule
Hope this helps