[
{
    "groupId":1,
    "groupName":"Семья",
    "members":[
    {
        "id":1,
        "nick":"coldunox",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    },
    {
        "id":2,
        "nick":"fred",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    },
      {
        "id":3,
        "nick":"tom",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    },
    {
        "id":4,
        "nick":"jackson",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    }
    ]
},
{
    "groupId":2,
    "groupName":"Работа",
    "members":[
    {
        "id":1,
        "nick":"west",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    },
    {
        "id":2,
        "nick":"cool_man",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    },
      {
        "id":3,
        "nick":"tedd",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    },
    {
        "id":4,
        "nick":"alisa",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    }
    ]
},
 {
    "groupId":3,
    "groupName":"Другие",
    "members":[
    {
        "id":1,
        "nick":"coldunox",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    },
    {
        "id":2,
        "nick":"coldunox",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    },
      {
        "id":3,
        "nick":"coldunox",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    },
    {
        "id":4,
        "nick":"coldunox",
        "firstname":"Павел",
        "lastname":"Широков",
        "email":"Paul_74128_14@mail.ru",
        "number":89053602244
    }
    ]
}

$.ajax({
type: 'GET',
url: 'json_data.json',
data: { get_param: 'value' },
dataType: 'json',
success: function (data) {   ?? }});

<div id="contact_form" >
<ul >
    <li >
        <label for="fname">Имя:</label>
        <input class="input" type="text"  placeholder="Иван" />
    </li>
     <li>
        <label for="lname">Фамилия:</label>
        <input class="input" type="text"  placeholder="Иванов" />
    </li>
    <li>
        <label for="mobile">Телефон:</label>
        <input class="input" type="text"  placeholder="89605402211"/>
    </li>

    <li id="last">
        <label for="email">Email:</label>
        <input  class="input" type="text" placeholder="ivan_ivanov@example.com"  />
    </li>
</ul>