Do i have the right to prove my innocence?

There are a multitude of issues which you have raised in your question. As far as keeping your job, Nevada is an at-will employment state where your employer can dismiss you for no reason at all, so long as it is not a prohibited reason. "Since employees in Nevada are presumed to be at-will, an employer can dismiss an at-will employee with or without cause, so long as the dismissal does not offend this state's public policy. State of Nevada v. Dist. Ct. (Anzalone), 118 Nev. 140, 151, 42 P.3d 233, 240 (2002)." While there are limited exceptions to the at-will employment doctrine, the Nevada Supreme Court has made clear that these exceptions are “severely limited to those rare and exceptional cases where the employer's conduct violates strong and compelling public policy.” Sands Regent v. Valgardson, 105 Nev. 436, 440, 777 P.2d 898, 900 (1989). The alternative question which you post implies is that other employees and/or your employer may be lying about you and publishing false facts, which may adversely impact not only your current position but ability to obtain employment in the future. These statements may be defamatory and should be investigated and all evidence preserved.