Here is the pure HTML and CSS solution.
We create a container box for navbar with position: fixed; height:100%;
Then we create an inner box with height: 100%; overflow-y: scroll;
Next, we put out content inside that box.
Here is the code:
.nav-box{_x000D_
position: fixed;_x000D_
border: 1px solid #0a2b1d;_x000D_
height:100%;_x000D_
}_x000D_
.inner-box{_x000D_
width: 200px;_x000D_
height: 100%;_x000D_
overflow-y: scroll;_x000D_
border: 1px solid #0A246A;_x000D_
}_x000D_
.tabs{_x000D_
border: 3px solid chartreuse;_x000D_
color:darkred;_x000D_
}_x000D_
.content-box p{_x000D_
height:50px;_x000D_
text-align:center;_x000D_
}
_x000D_
<div class="nav-box">_x000D_
<div class="inner-box">_x000D_
<div class="tabs"><p>Navbar content Start</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content</p></div>_x000D_
<div class="tabs"><p>Navbar content End</p></div>_x000D_
</div>_x000D_
</div>_x000D_
<div class="content-box">_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
<p>Lorem Ipsum</p>_x000D_
</div>
_x000D_