JSFiddle - React, Tailwind, and code Playground

HTML

<div class="col-md-10">
  <input class="js-radio" id="SelectedRoleType" name="SelectedRoleType" type="radio" value="JobSeeker"> Job Seeker
  <input class="js-radio" id="SelectedRoleType" name="SelectedRoleType" type="radio" value="Referrer"> Referrar
</div>      
<div class="col-md-10">
  <input class="form-control" id="Email" name="Email" type="text" value="">
</div>

CSS

/* just to see it is required */
input[required] {
  border-color: red;
}

JavaScript

$('[name="SelectedRoleType"]').on('change', function(e) {
  e.target.value === "Referrer"
    ? $('[name="Email"]').show().attr('required', true)
    : $('[name="Email"]').hide()
});