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You may be missing two things to get your Grid to show up.

Add this file:

app/code/community/VivasIndustries/SmsNotification/Block/Adminhtml/Sales/Status.php

<?php
class VivasIndustries_SmsNotification_Block_Adminhtml_Sales_Status extends     Mage_Adminhtml_Block_Widget_Grid_Container
{

public function __construct()
{

    $this->_controller = 'adminhtml_sales_status';
    $this->_blockGroup = 'smsnotification';
    $this->_headerText = Mage::helper('smsnotification')->__('SMS Notifications');
    parent::__construct();
}


protected function _prepareLayout()
{
   $this->setChild( 'grid',
       $this->getLayout()->createBlock( $this->_blockGroup.'/' . $this->_controller . '_grid',
       $this->_controller . '.grid')->setSaveParametersInSession(true) );
   return parent::_prepareLayout();
}

}

And this file:

app/design/adminhtml/default/default/layout/smsnotification.xml

<layout>
    <adminhtml_smsnotification_index>
        <reference name="content">
            <block type="smsnotification/adminhtml_smsnotification" name="smsnotification" />
        </reference>
    </adminhtml_smsnotification_index>
</layout>

You may be missing two things to get your Grid to show up.

Add this file:

app/code/community/VivasIndustries/SmsNotification/Block/Adminhtml/Sales/Status.php

<?php
class VivasIndustries_SmsNotification_Block_Adminhtml_Sales_Status extends     Mage_Adminhtml_Block_Widget_Grid_Container
{

public function __construct()
{

    $this->_controller = 'adminhtml_sales_status';
    $this->_blockGroup = 'smsnotification';
    $this->_headerText = Mage::helper('smsnotification')->__('SMS Notifications');
    parent::__construct();
}


protected function _prepareLayout()
{
   $this->setChild( 'grid',
       $this->getLayout()->createBlock( $this->_blockGroup.'/' . $this->_controller . '_grid',
       $this->_controller . '.grid')->setSaveParametersInSession(true) );
   return parent::_prepareLayout();
}

}

And this file:

app/design/adminhtml/default/default/layout/smsnotification.xml

<layout>
    <adminhtml_smsnotification_index>
        <reference name="content">
            <block type="smsnotification/adminhtml_sales_status" name="smsnotification" />
        </reference>
    </adminhtml_smsnotification_index>
</layout>

In your etc/config.xml, add this in the <adminhtml> tag:

  <layout>
        <updates>
            <smsnotification>
                <file>smsnotification.xml</file>
            </smsnotification>
        </updates>
    </layout>

I haven't tried installing all of your code locally to really dig into it but one thing that stands out is your _prepareCollection() in your grid.

Replace your _prepareCollection() with this:

protected function _prepareCollection()
{
    $collection = Mage::getModel('smsnotification/smsnotification')->getCollection();
    $this->setCollection($collection);
    return parent::_prepareCollection();
}

You may be missing two things to get your Grid to show up.

Add this file:

app/code/community/VivasIndustries/SmsNotification/Block/Adminhtml/Sales/Status.php

<?php
class VivasIndustries_SmsNotification_Block_Adminhtml_Sales_Status extends     Mage_Adminhtml_Block_Widget_Grid_Container
{

public function __construct()
{ 

    $this->_controller = 'adminhtml_sales_status';
    $this->_blockGroup = 'smsnotification';
    $this->_headerText = Mage::helper('smsnotification')->__('SMS Notifications');
    parent::__construct();
}


protected function _prepareLayout()
{
   $this->setChild( 'grid',
       $this->getLayout()->createBlock( $this->_blockGroup.'/' . $this->_controller . '_grid',
       $this->_controller . '.grid')->setSaveParametersInSession(true) );
   return parent::_prepareLayout();
}

}

And this file:

app/design/adminhtml/default/default/layout/smsnotification.xml

<layout>
    <adminhtml_smsnotification_index>
        <reference name="content">
            <block type="smsnotification/adminhtml_smsnotification" name="smsnotification" />
        </reference>
    </adminhtml_smsnotification_index>
</layout>

If this is what you have in:

/app/code/community/VivasIndustries/SmsNotification/Block/Adminhtml/Sales/Status/Grid.php:

I haven't tried installing all of your code locally to really dig into it but one thing that stands out is your _prepareCollection() in your grid.

Replace your _prepareCollection() with this:

protected function _prepareCollection()
{
    $collection = Mage::getModel('smsnotification/smsnotification')->getCollection();
    $this->setCollection($collection);
    return parent::_prepareCollection();
}