After 10th I did 4. yrs diploma in Mech. Engg. followed by 10 yrs work exp. I now want to pursue teaching in school.Can I apply for BeD?

For pursuing B.Ed. the eligibility is graduation. In your case, since you are a diploma holder, admission to B.Ed. is not possible.

Hi, Aspiring teachers have several options available to them. Some teachers begin their careers by earning a bachelor's degree in education from an accredited college or university. Also all prospective teachers must participate in professional fieldwork, often included in education degree programs