If redundancy is involuntary, then approaching retirement does not affect your rights.
However, rather than force people to leave, many firms first offer voluntary redundancy and to make that attractive employees will generally be offered better terms than they would get under involuntary redundancy.
Early retirement is not a form of redundancy: it is an alternative to redundancy. If you choose the early retirement option, you will have no redundancy rights and you will not receive a redundancy payment.
Why would you opt for early retirement then? Because, typically, an employer will offer incentives along with the early retirement option, such as a large lump-sum payment.