where put html form in Res folder and how to show this html form in webview.

Indeed place your html page in the assets folder. For showing the webpage use a WebView

WebView wv = (WebView)findViewById(R.id.webview);
wv.loadUrl("file:///android_asset/index.html");
or
String str = "...."; webview.loadData(str,"text/html","UTF-8");