What is the process for clearing an F grade (backlog) in a MOOC?

If anyone has any clarity about this process please share what is to be done, what's the timeline for doing the same MOOC on NPTEL again, about the certificate submission and how much has to be paid to DTU apart from the 1000 to be paid to NPTEL for the exam registration fee? Considering that DTU resources are not used at all, the usual 7500 fee doesn't make sense n?