It might help if you can provide the exact type of ‘extender’ that you have?
Also what is the exact type of Nikon 200mm that you have? The more info of type/markings, etc will enable people to possibly assist you.

The following link is an index with pages and pages of the various Nikon variants of ‘extender/teleconverter’.

There are also compatibility charts for ‘extenders’teleconverters’ and lenses.

http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/teleconverter/index.htm

TJ