HI I have a logs with field IP_range =1.2.3.0-1.2.3.255, Can I convert to CIDR range like 1.2.3.0/24?
You could certainly create a custom search command to do this, and use an existing Python library to do that specific field calculation. A quick googling suggests the netaddr library may do what you need.
Short of some form of custom code (search command, maybe a scripted lookup), I'm not sure you can do that in native SPL.