Teacher

For assistant professor master degree is required with NET. For associate and professor PhD is the main requirement with other professional activities.

For being a professor you must be post graduate.then you have to clear the NET entrance also. Phd will be greatly accepted.

Some colleges give off time for study,

Yes, of course.

Dear Afzal,
If your wife having aim for teacher than she can pursue B.ed for school teacher otherwise she can go for Net exam than apply for College level professorship and even she start teaching profession after Phd programme too.
So decide the way according to her interest and passion.
All the best

You should opt for M.Tech. It has more career options in teaching. Teaching in engineering colleges demands to have at least M.Tech. from aspirants who wish to join as teacher or lecturer .
All the best.