As trustee want close trust w 2024 filing. No trust 2024 income but small amount of cash remains to be distributed to 3 beneficiaries. Can i distribute now w K-1's (Feb 2025) and claim on 2024 return using Section 663(b) election = + 65 days rule?

[M-MTax]

You can make the 663(b) election if the distribution is made within 65 days of the close of the trust's tax year.

However, you are not required to file a return if the trust has neither income nor gains (or otherwise incurred any expenses (deductions) or received any tax credits). 

Regardless, you can file a return marked as "final" to officially close out the (terminated) trust with the IRS.