1. Add below permission in manifest file :
2. Use below code for phone call.
<uses-permission android:name="android.permission.CALL_PHONE" />2. Use below code for phone call.
String mobileno = "9999999999";
String uri = "tel:" + mobileno.trim() ;
Intent intent = new Intent(Intent.ACTION_CALL);
intent.setData(Uri.parse(uri));
startActivity(intent);