Hi @piyush walia
If I understand your question correctly, I'd recommend using clearProps rather than jQuery's removeAttr() method. I think if you change your reset function a bit, you should see the desired behavior. Please try this:
function reset(){
TweenLite.set(".block_1, .av2", {clearProps:"all"});
$(".block_1").addClass('block_2').removeClass('block_1');
$(".av2").addClass('block_1').removeClass('block_2');
};
Hopefully that helps. Happy tweening.