It depends on which country you are offered. For example if you are offered to US, there will be a list of universities that you will be applying to. The list of universities is normally based on the course ranking of the nation and Petronas will use the reports from eg: Gourman University ranking report, QS report etc etc. Petronas do have recommended Universities for their students to apply to but you are still free to choose other unis from the list.
About the interview, hmm.. Basically, there are two types of interview namely the individual and group. They are seeking for cooperation qualities and maturity in you. These are just a brief summary on the interview part.