The word isn't occupation by the way, however, it is subsumed under the meaning of the word that I am looking for.
I'll give a few examples in order to elucidate the meaning:
'The gentleman reserved her ______'
'By having his uncle murdered, he could take up the long awaited ____ as King of England'.
'The man asked whether he could take my ____ in line, as his cat was in labour'.
To be precise on what am looking for, it's about someone who has some sort of right to a given position (physical or abstract), of varying degree (from the line at the cheque point, right up unto the throne).
This means that 'place', whilst it does work for all three examples, is not the word am looking for, since you can have a place in say, the middle of the ocean, but no one has right to it (Well to be honest someone probably does for some silly reason).