In my application am displaying 20 multiple choice questions with the help of RecyclerView.
If I change the value of first RadioGroup and s         
        
Inside your student class add a boolean variable isSelected. Now on checkedChangeListener of each radiogroup, change the value of isSelected to mark whether some value has been selected or no selection has been made. Now inside onBindViewHolder() just do
    if(stList.get(position).isSelected){
  viewHolder.rgAnswers.check(stList.get(position).getSelectedRadioButtonId());
    }else{
    viewHolder.rgAnswers.clearCheck();
    }
At the end you can iterate over the whole list and check for which objects, isSelected is true