I'm having difficulty getting org-babel to evaluate this block of code with 

 
>emacs v24.5<br/>
node v5.0.0<br/>
babel-node v.6.6.5

<pre><code> #+BEGIN_SRC js :cmd "babel-node"

 let arr = [1, 2]; 
 let [x, y] = arr;
 
 console.log(x);
 console.log(y);

 #+END_SRC
</pre>
<br />
The output looks like this

<pre><code>/tmp/babel-3700Vaq/js-script-37003RN:2<br />
let arr = [1, 2];
^^^

SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode
 at exports.runInThisContext (vm.js:53:16)
 at Module._compile (module.js:404:25)
 at loader (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:126:5)
 at Object.require.extensions.(anonymous function) [as .js] (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:136:7)
 at Module.load (module.js:356:32)
 at Function.Module._load (module.js:311:12)
 at Function.Module.runMain (module.js:457:10)
 at /usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:161:27
 at Object.<anonymous> (/usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:162:7)
 at Module._compile (module.js:425:26)*

</pre>

But this source block seems fine

<pre><code>
 #+BEGIN_SRC js :cmd "babel-node"
 const numbers = [10,20,30,50];
 const multiplyBy10 = numbers.map(a => a * 10);
 console.log(multiplyBy10);

 #+END_SRC

 #+RESULTS:
 | 100 | 200 | 300 | 500 |
</pre>

<br/>
>Edit:
Added self executing function with "use strict" 

<pre><code>
#+BEGIN_SRC js :cmd "babel-node" 
(function xy() {
"use strict";
let arr = [1, 2];
let [x, y] = arr;
console.log(x);
console.log(y);
})()

#+END_SRC

#+RESULTS:
</pre>

The output looks like this
<pre><code>
/tmp/babel-13529OHt/js-script-13529MVq:6
 let [x, y] = arr;
 ^

SyntaxError: Unexpected token [
 at exports.runInThisContext (vm.js:53:16)
 at Module._compile (module.js:404:25)
 at loader (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:126:5)
 at Object.require.extensions.(anonymous function) [as .js] (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:136:7)
 at Module.load (module.js:356:32)
 at Function.Module._load (module.js:311:12)
 at Function.Module.runMain (module.js:457:10)
 at /usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:161:27
 at Object.<anonymous> (/usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:162:7)
 at Module._compile (module.js:425:26)
</pre>

<br />
> Edit: Thanks to @ebpa i've managed to solve it with
<pre><code>npm install -g babel-preset-es2015</pre>

<br />
This is the output i'm getting after evaluating the default source block, which doesn't have a self executing function wrapper. 

<pre><code>
/usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:372
 throw new Error("Couldn't find preset " + JSON.stringify(val) + " relative to directory " + JSON.stringify(dirname));
 ^

Error: Couldn't find preset "es2015" relative to directory "/tmp/babel-270346ez"
 at /usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:372:17
 at Array.map (native)
 at OptionManager.resolvePresets (/usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:364:20)
 at OptionManager.mergePresets (/usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:348:10)
 at OptionManager.mergeOptions (/usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:307:14)
 at OptionManager.init (/usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:465:10)
 at compile (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:81:45)
 at loader (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:126:14)
 at Object.require.extensions.(anonymous function) [as .js] (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:136:7)
 at Module.load (module.js:356:32)
</pre>

<br />

>Edit: Fire up a terminal and ran babel-node 
<br />

<pre><code>
> require('babel-preset-es2015');
</pre>

Output
<pre><code>
Error: Cannot find module 'babel-preset-es2015'
 at Function.Module._resolveFilename (module.js:337:15)
 at Function.Module._load (module.js:287:25)
 at Module.require (module.js:366:17)
 at require (module.js:385:17)
 at repl:1:1
 at Object.exports.runInThisContext (vm.js:54:17)
 at _eval (/home/johnwind/.nvm/versions/node/v5.0.0/lib/node_modules/babel-cli/lib/_babel-node.js:102:26)
 at REPLServer.replEval (/home/johnwind/.nvm/versions/node/v5.0.0/lib/node_modules/babel-cli/lib/_babel-node.js:187:14)
 at bound (domain.js:280:14)
 at REPLServer.runBound [as eval] (domain.js:293:12)
</pre>