Ther first 6 letter are the most confusing part of the word 'INDIVIDUAL'. Here is the tip to remember the spelling of 'INDIVIDUAL' correctly.
An Individual is Indivisible
An Individual is one single person and he cannot be divided further, so he can be thought of an indivisible object. The word 'Indivisible' will remind us that ther is an 'i' at the 4th location.