Hey,

These days certificate course in fire and safety management is very useful. Almost every industry needs safety officers as it is one of the most important thing in any company. And so, you can go for it. The institute that provide this course also offer placements and jobs.
You can also do software courses like AutoCAD, solid works, CREO ,etc. They are all in demand in mechanical industries.
Other than this, you can learn CNC or other machines and you will easy get a job. You can do material management course, automobile mechanic course, etc.

Also, there is vacancy for diploma engineers too, so you can directly join any industry on the basis of diploma.

Hope this helps!