This might be pretty basic but i am not able to find out what is wrong here. I have a react form in which i am using a custom select box to list the students. I want to clear the selection when isChecked is set to false.

 let studentId = watch("std.id"); // is of type number
      
<Select
 name="std.id"
 placeholder="Select Students"
 registerResult={register("std.id")}
 list={studentList}
 disabled={!isChecked}
/> 

I tried emptying with "" the value also tried assigning it to null like below, but didnt work. can anyone tell me why is it not resetting?

if(!isChecked){
  studentId = null;  //Select box still shows the selected value even after this
}