Either "Model" is null, or "Model.Records" is null, use the debugger to find out why. I'm guessing it is Model though as you're not passing a model to your view.
return View("Index");
to pass a model you use the second param
return View("Index", ????);
We don't know what ???? is as we don't know your logic or your view code. It might be
return View("Index", i);
We don't know. This is all very basic MVC stuff though, I'd recommend you go through a book on MVC to at least understand the basics or else you're going to struggle.