I'm not certain you'd need an N-reg aircraft or TSA approval
For type ratings or your initial license/multi/IR, yes TSA is required. Does this person already have FAA certificates?
If they are just going up in a seneca not necessarily. Don't forget no endorsement needed for the checkride. Training is of course recommended.
The examiner would have to be FAA approved, so not really enough information here to go on.
Alex.