You can simply define a public accessor function to read the value of h.
Something like :
Code: C++
void getdata()
{
    cout<<h;
}

So, your test program becomes :
Code: C++
#include<iostream.h>
#include<conio.h>

using namespace std;

struct emp
{
private:
    int h;

public:
    void setdata(int a)
    {
        h = a;
        cout<<h;
    }

    void getdata()
    {
        cout<<h;
    }
}emp1;

int main()
{
    cout << "Initialised emp1.h with : ";
    emp1.setdata(5);
    cout << endl;
    getch();
    cout << "Reading value of emp1.h : ";
    emp1.getdata();
    cout << endl;
    getch();
    return 0;
}