Dear Siddharth,

Firstly, after adding the choices in the list you can change the sequence by moving them up or down, interchange choices and delete choices. It is advisable to lock the choices because if you will not lock their choices then the saved choices will get locked. If there are no saved choices then it will be considered that you have not selected any choices and as a result will not be considered at the time of NEET seat allotment. 

Hope this helps!