can i deploy SNMP modular input on running Splunk without having an SNMP software on the network
This SNMP modular input is the software to get/walk/pull/push to the devices that are supporting SNMP as protocol and most important it's enabled.
I'm pretty surethis question has not been answered since it's not clear at all.
My advice is to read more about the SNMP as protocol and capabilities then come back and make some clarification about the question