Joining models in eloquent Laravel 5.3

I am new to Laravel. Here is my schema:

Schema::create('cluster_info', function (Blueprint $table) {
            $table->increments('id');
            $table->string('code')->unique();
            $table->string('pa_lastname');
            $table->string('pa_firstname');
            $table->string('pa_middlename');
            $table->string('pa_suffix');
            $table->integer('branch_id');
            $table->timestamps();

        });
 Schema::create('cluster_grouping', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('cluster_id');
            $table->integer('client_id');
            $table->timestamps();

        }); 
 Schema::create('branch', function (Blueprint $table) {
            $table->increments('id');
            $table->string('code')->unique();
            $table->string('name');
            $table->string('region');
            $table->timestamps();

        });

I want to join cluster_info to the branch. So in my Cluster_Info Model:

 public function Branches(){
        return $this->hasOne('App\Branch');
    }

and when I call it in my control it has null values

$cluster = new App\Cluster_Info;
dd($cluster->Branches());

via Chebli Mohamed