[_detailsWebView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource: _htmlFile ofType:@"html"] isDirectory:NO]]];

-(void)loadHTMLFiles:(NSString*)htmlFile
{
    //I assume u have set IBOutlet of detailsWebView
   [_detailsWebView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:htmlFile ofType:@"html"] isDirectory:NO]]];
}

[ViewController *objViewController = [ViewController alloc]init];
 //here newView is pushed in navigation or add SubView
[objViewController loadHTMLFiles:yourHTMLFileName];