Hey there,
@Muneef! cPanel Reseller packages are called ACLs, which is what the resellers themselves have access to on the system. Depending on what you allow the reseller to create, they would be able to log in to their limited version of WHM and create packages normally.
I can't provide much detail about the WHMCS side of things, so you may want to reach out to their community directly at
WHMCS.Community for more details.