Given the head of a singly linked list, group all nodes based on the remainder when their indices are divided by 3 (i.e., indices % 3). Rearrange the list so that nodes with the same remainder are grouped together, and the groups appear in the order of increasing remainder values (0, 1, then 2). Return the head of the reordered linked list.
Consider the 1st node to have index 1 and so on. The relative order of the elements inside each group must remain the same as the given input.