For example, when referring to a single entity, I could single someone out by calling them an "individual particular" because the words "individual" and "particular" are interchangeable in this context. It would seem that two words that are close enough in definition to be swapped to produce a phrase of the same meaning are redundant.
To me, the phrase "particular individual" is useful when describing one who is fastidious or extraordinary, not just individual.
But is "particular individual" truly redundant? If particular is being used here in the sense of singling out one from a group (in the way that you might say "this particular car" or "this particular company" or "this particular person" as opposed to all the other cars/companies/people you could have identified) then it would seem to be a proper usage. There is a subtle distinction, which would be more evident in context, between "this particular individual" and "this individual"