Some people think that JR Passes cover their way to Nikko.
Well, you can use the Shinkansen to JR Utsunomiya for an hour and change to local line and have a 45 minute ride, but other ways are more convenient.
https://www.japan-rail-pass.com/japan-by-rail/itineraries/tokyo-nikko
I choose different trains based on the places you start from.