I have submitted the Online Application. Should I send the printout of the application to the IOCL by post/by hand?

No. You need not send the hardcopy printout of application. However you need
to carry the print out of your application, duly signed, when you appear for the
written examination.

The job details and information in post has been prepared for recruitment updates, advise to use for informational purposes only. for the proper and exact details kindly refer official website of that organization. For more Click here