So even if you are a mechanical engineer but you function, perhaps, as a Computer and Information Systems Manager (NOC 0213) then you might as well use that code.
dont worry about education (unless you are a doctor or something). Look for a NOC code of a software person (2173 , 0213, etc). Only 0213 is on the ministerial list but you must have management experience.
as rupesh said, If you had been a manager then you are now eligible to apply.
edu and job exp dont need to matched. Whats your designation and post's name at the moment?