Is work experience necessary for MBA?

As such it is not essential to have work experience for doing MBA. However, there may be some institutions which are demanding this but they must be quite rare. In my opinion if one plans to do MBA through distance education then perhaps work experience of 3 to 5 years would make the studies easy an

No, its not necessary.

Yes, ISB asks for a minimum of 2 years full-time work-experience for admission to its management courses.