JSFiddle - React, Tailwind, and code Playground

HTML

<b>ресультат height: </b><span id="res"></span>

<div class="wapper_important_news clearfix">
  <div class="i_n_static fs36 regular">ВАЖНО!</div>
  <div data-rel="n" class="i_n_block clearfix" >
    <div class="left">
      <div class="i_n_date fs13 light">DATE</div>
    </div>
    <div class="right">
      <div class="table-cell">
        <a href="#href" class="underline">
          <div class="i_n_title fs16 bold">TEXT_HREF222</div>
        </a>
        <div class="i_n_desc fs16 light">TEXT22222</div>
      </div>
    </div>
  </div>
	<div data-rel="n" class="i_n_block clearfix" style="visibility: hidden;">
    <div class="left">
      <div class="i_n_date fs13 light">DATE</div>
    </div>
    <div class="right">
      <div class="table-cell">
        <a href="#href" class="underline">
          <div class="i_n_title fs16 bold">TEXT_HREFTEXT_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HRE33TEXHREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF3333333333</div>
        </a>
        <div class="i_n_desc fs16 light">TEXTTEXT_HREF3XT_HREF3333T_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF33333TEXT_HREF3333T_HREF33333TEXT_HREF33333TEXT_XT_HREF33333TEXT_HREF33333TEXT_HREF3333333333</div>
      </div>
    </div>
  </div>
  <div class="i-n-control">
    <div class="left">ww</div>
    <div class="right">ee</div>
  </div>
</div>

CSS

.right{
	diplay:block;
	width:50px;
	word-wrap: break-word
}

JavaScript

var a = $(".i_n_block:visible");
$(".wapper_important_news").height(a.next().find(".right").height());
$("#res").text(a.next().find(".right").height())