Paralysisof 3rd, 4th, 6th nerves with involvement of ophthalmicdivisionof5thnerve, localizes the lesion to
Ipsilateral ophthalmoplegia  causing diplopia occur due to 3rd, 4th  & 6th cranial nerves.
6th nerve passes through cavernous sinus and others are related to the lateral wall of cavernous sinuses.
Apex of orbit
Brainstem
Cavernous sinus
Base of skull