NPTEL is a joint initiative by IITS and IISc to offer online courses and certification in various topics.

On NPTEL you get free access to various different courses and able to get certificate by paying 1100 rs with passing certification exam.

NPTEL  certificate you can use in your resume .Exam is having with credit points which is consider by related companies in that field.

It helps in getting your internship.

Some of the courses are mandatory in engineering college.

Certification can be get in 4weeks ,8 weeks and 12 weeks program by giving Exam at the end.

For more information use this link https://onlinecourses.nptel.ac.in/

I think this information is quite enough .If any queries remain than comment below , we are  here for solve your queries