Background check for job in defense sector.

Hello, I'm an Indian national, I did my masters in the EU as part of Erasmus Mundus. There is a prospective job offer, however, the company works a little in the defense sector. They're looking for a security check which is the usual for such positions. However, they just mentioned that the Indian government doesn't allow such checks. I don't think that is the case, does anyone have any idea what kind of check is this and what is the procedure for it?