Hi Swati,
You can load the MIB file in any MIB browser for eg. Ireasoning. Once you do this you just need to click on SNMP MIB , the OID will be shown on the OID bar at the top of the browser. I have attached sample snapshot for the same.
I am not able to understand your query "which command we see that mib file is already present on the node?"
Can you just explain in detail what you are looking for.
Regards,
Rishi