how to insert radio button selected value using mvc?

See this simple example from that you will get some idea.

VIEW :
<%using (Html.BeginForm())
{ %>
<%=Html.RadioButton("Gender", true) %>Male
<%=Html.RadioButton("Gender",false) %>Female

<%} %>

MODEL :

public class HomeModel
{
public int Id{get; set;}
public bool Gender{get; set;}
}

CONTROLLER :

public ActionResult Index()
{
return View();
}
[HttpPost]
public ActionResult Index(HomeModel hm)
{
var gen = "N";
if (hm.Gender ==true)
  gen = "M";
else
  gen = "F";

Tab1 obj = new Tab1();
obj.Id = 1; // Your id
obj.Gender = gen;
// Your Save Logic goes here
return View();
}