Suggestion needed

Hi guys,

I am a mechanical engineer with MBA in finance & international business (both from india). Currently, I am working abroad in Riyadh in a trading firm (in their accounts department). I wish to have a boost in my career and have been toying with the idea of going in for a GMAT or GRE to gain further education and thereby get access to better job prospects. Please suggest the better option in my case i.e. GRE or GMAT and any specific areas of specialization that might be suitable to my engineering & finance backgrounds.