if we implement interface in structure and create object of structure then the object of structure stores in stack or heap

thanks for reply.

Do you mean "stack or heap"?
 
An interface does not have an implementation so it is not allocated anywhere. When the xyz struct is declared, it will exist in the stack, correct? That would include the string name. Are you asking because you are not sure whether xyz.name will be modified in functions without ref? Try it and see.
 
using System;
namespace TestConsole
{
public interface iface
{
string name { get; set; }
void show();
}
struct xyz : iface
{
public string name { get; set; }
public void show() { }
}
class Program
{
static void Main(string[] args)
{
xyz test = new xyz();
test.name = "Initial";
WithoutRef(test);
Console.WriteLine(test.name);
WithRef(ref test);
Console.WriteLine(test.name);
}
static void WithoutRef(xyz test)
{
test.name = "WithoutRef";
}
static void WithRef(ref xyz test)
{
test.name = "WithRef";
}
}
}