Can we use Milestone 2016 SDK to connect Milestone 2024/2025 VMS

Can we use the Milestone 2016 SDK to integrate with Milestone VMS versions 2024 or 2025?

No.

We recommend using the newest MIP SDK.

https://developer.milestonesys.com/s/article/about-MIP-SDK-compatibility-with-XProtect-product-versions