If you decide not to continue working.
Do you have any income at present ?
If you don't and you defer your pension you will miss out on Income tax credits for the years without income. You could drawdown an amount of pension, income tax free, during these years.
You should sign on for Prsi class A credits.
If you take up employment for 13 weeks in any calender year at age 61, 62, 63, 64 or 65 (if your 65th birthday is over 13 weeks into that year) and have at least 39 A class Prsi contributions in the year of your 63 birthday (credits suffice) you will qualify for the 65s benefit ( 220 euro per week for 52 weeks). You only need to earn 38 euro per week to gain a class A contribution so a few hours per week is all that is needed.