Nptel is supposed to be as informative as the classrooms but unfortunately I dodnt found the overall program is not very interactive.
Modules are very long and it makes it difficult to complete courses.They should have animations as well for better explanation, I took lecture on Electric Machines in which instructor tried to explain the synchrounously revolving field in a verbal way.
Crucial concepts like Magnetism and Electricity should have well animated videos with labels.
Student community support should be built so that students taking lectures could reach out to other students for discussion.
I would reccomend other platforms like Edx, Udacity or Lynda compared to Nptel.