Hi Nikhil,
As already answered by other experts, you can re-package (or probably use it as is if it is designed in teh same fashion) as a custom action and uploadit in MII 'System Resources -> Custom Actions' section. Then deploy the custom action and check in the log viewer if the deployment was done successfully without errors.
If the custom action was successfully deployed, you would be able to see the action blocks in the MII workbench when you try to create/edit a transaction. You can then use these blocks and pass the related input parameters and get the result back.
Link to a tutorial about using/writing custom actions:
https://help.sap.com/saphelp_mii122sp03/helpdata/en/4c/8cee70f2bd60c5e10000000a15822d/content.htm
Hope this helps!
Regards,
Saumya Govil