What advice i should give to him..

He should retain possession of his actual passport. Company HR can easily inspect it and make a photocopy of it if they really need the record, but he should not be mailing it to them or anything like that.

It depends.

If they're not going to obtain a visa for him, then he should just make a photocopy of the pertinent page(s) and give them that because all they need is the passport number and proof that he does have one.

If, however, they are going to be obtaining the travel official documentation for him, they will need to submit his passport to the consulate. I had to do that when I went to Brazil. The consulates do need to see the original passport.