MBA admission selection panel will keenly watch you on your leadership qualities and soft skills of communication and body language.
You need to be agile and have presence of mind to take initiative in GD. But you must be very cautious not to shout or raise your voice for taking lead.
Opportunity of taking initiative will continue to come in entire GD at regular intervals. over here Initiative means to come up with strong idea which can be discussed further based on assigned GD topic.
Ideal situation would be to speak on GD topic in such a way that other co group members also discuss the similar points and that will establish your leadership qualities.
Practice with various GD topics and get success.