What's the scope of NEBOSH for an MBA professional who wants to change the career path from finance to Safety? And how much is the chance of Success?

No problem. you can develop your career  by doing NEBOSH 

The purpose of NEBOSH, IOSH and other certification organizations is to see to it that the safety practitioner whether he is a former accountant is qualified by passing their requirements. This is easy to pass for personnel related to the construction Industry and Oil & Gas. The chance of success for an accountant is I would say not easy because HSE is all about Engineering and if your background is MBA then the company will rather select the Engineer rather than the accountant.

MANY STUDENT PROFESSIONAL ASK US THE DIFFERENT  BETWEEN NEBOSH IOSH WHICH ARE DEMAND BY ORGANIZAAAAATION  FOR THE JOB  IN THE OCCUPATION  HEALTH AND SAFTY  QUALIFICATION