Where can I get job after graduating with mechanical engineering and NEBOSH IGC?
Anywhere, try hard submitting your resume.
Nevertheless, you can explore the internship/apprenticeship programs in your country to start with. Or even work for free to get the experience, and publicize yourself and start building network.
I do know that for example in our country there are lots of companies associated heavy or light industries\production plants which you can catch a suitable positions as a jr. safety officer or non safety related jobs. (for ex foreman) But however you like maybe cannot find out a job matched to your profile, because it also depends on your induvidual character if you are a calm nature man or lil bit agressive, maybe you have got a theoretical knowledge but cannot apply them in day to day activities etc. These all are very important aspects in your professional career. But I can make you sure, if you`re eager to be a safety guy in close future and as you said that you are a NEBOSH qualified with technical education, then don`t worry maybe firstly you will be needed for many of local companies as a safety representative if you don`t mind of course. Afterall it depens on your attitude, behavior, motivation etc.))
a little consultation for just beginners