<option class="options" value="allinone" id="puneid" >Pune</option>
       <option class="options" value="1">pune-loc</option>
    <option class="options" value="2">pune-loc1</option>
    <option class="options" value="3">pune-loc2</option>
    <option class="options" value="16">pune-loc3</option>

    <option class="mumbai" value="allinone" id="mumbaiid" >Mumbai</option>
    <option class="mumbai" value="1">mum-loc</option>
    <option class="mumbai" value="2">mum-loc1</option>
    <option class="mumbai" value="3">mum-loc2</option>
    <option class="mumbai" value="16">mum-loc3</option>
    <option class="mumbai" value="26">mum-loc5</option>
</select>

$('#siteSelector').click(function(){
    var self = $(this);
    if(self.val() == 'all'){
       self.children().prop('selected',true).click()

    }
    else
    {
        self.find('.options:first').prop('selected', false)
    }
})
$('#mumbaiid').click(function(){
     var self = $(this);
    if(self.val() == 'allinone'){

       self.children().prop('selected',true).click()

    }
    else
    {
        self.find('.mumbai:first').prop('selected', false)
    }
    })