Dear aspirant,

Choice locking or choice filling as some say is the list of college where you'd like to get a seat in. It has to be done in the descending order of you preference or importance. Which ever college you think is best should always be on top.Once you have dome it click submit or okay or any button that will submit the list and make it uneditable untill the round is over.This is called choice locking. And since you might have done it for previous round, The same list should go ahead without the names of the colleges below the college that has been assigned to you i think