Which model to use

[Alex26]

Good afternoon,

This issue may not concern EViews at all, however I am seeking for an econometric advice.
I am doing a research in dependence of corruption on FDI inflows. I have 4-5 more independent variables alongside corruption . Previous works used GLS model however I don't think it will certainly show the causality...
Therefore, wanted to ask which model shall I use.
I have got data over 34 countries for 15 years. Should it be Granger , VAR or VECM or maybe any other?
Sorry if the question is off-topic or too stupid, but desperately need help.

Thanks in advance.