Hey Gauri

Yes ofcourse a company secretary may work abroad after the completion of it's CS like either in UK or US but you have to go through some of the more work thereafter. As the laws you have studied here would change over there so you would be in great need to go through the other laws being obeyed in those other foreign countries. You may also need to do an another internship. So it is actually advised to stay in India as CS have a lot of scope here.