Hi @Emm1953 
Thanks for your question. With regards to Box 24 -Excess Amount: 

This is the taxable part of amounts received in the year that is more than the minimum amount. This amount is already included in box 16. Only report the box 16 amount on your return, if the amount received relates to RRSP contributions you could not deduct from income, you may be able to claim an offsetting deduction on line 23200. For more information, refer to Form T746, Calculating Your Deduction for Refund of Unused RRSP, PRPP, and SPP Contributions.