in django template after choice the radio option my rabio box dont get checked

 {% if mod %}

  {% for i in mod %}

  <div class="form-check">
    <input class="form-check-input" type="radio" name="Catagory" id="{{i.id}}"/>
    <label class="form-check-label" for= "{{i.id}}" >
      <a href="{% url 'catagory_wise_post' i.slug %}"> {{i.name}}</a> 
    </label>
  </div>
  


  {% endfor %}

  {% endif %}

here is the checking problem