It looks like you’re asking for a guide or write-up related to (or a similar OpenIV-based game) — specifically about updating a x64/dlcpacks folder for an add-on mod pack named mpsum , handling DLC RPFs , and downloading "top" mods or tools.
If you are searching for a direct download link for this file from a "Top" result on a modding site or a YouTube video, update x64 dlcpacks mpsum dlcrpf download top
Updating GTA V: Managing the mpsum dlc.rpf File Grand Theft Auto V It looks like you’re asking for a guide