I am trying to help my nephew get his car going. It's a 97 Prelude VTec Tiptronic automatic tranny with an H22A4 engine and the tranny is dead (won't catch any gears). I heard this tranny has a bad reputation.

Should I repair, replace with rebuilt same tranny or can I switch it for a 5-speed without changing anything else in the car?

 

I would swap to 5 speed, much better then the auto's Look in the FAQ or Search it. There is alot of info on this site about the swaps.
Read this https://honda-tech.com/forums/showth...ht=auto+manual

 

replace with rebuilt same tranny and sell car. Take that money and buy a 5-speed 97-01 Prelude. If you know how to advertise car and sell, you will get a good amount for the '97 with rebuilt tranny. Then when you buy a 5spd Prelude, hopefully you'll have some money left of the original sale to pay for all expenses .. car + tranny. Good luck.