My answer :
These are still untested territories. You can use NPTEL and other online courses to brush up on a subject or for an introduction to a subject. But frankly, just doing NPTEL and other online courses may not get a job, although these may add to your skillset and knowledge. So, dont bank on these courses to help you get a job or a promotion or admissions in different or same majors. Use these courses to enhance your knowledge and practice more so that you are better at your work.