Thinking of taking the 17 day northern italy tour. whats available to visit pompeii ,sorrento, amalfi and island of capri !!
That tour doesn't go further south than Rome. So you have 2 choices: the 13 day South Italy tour, or do it on your own. The latter is super easy to do. It all depends on how much extra time you have, and just what you're interested in seeing.
Right, If you want to visit Pompeii, Amalfi and Capri, you'll either want a different tour or add time to the back end of the BOI tour to do them on your own. CJ is spot on; the RS South of Italy Tour would be your choice if wanting to do those.
Do note that even on this tour, Capri would be a day trip you'd need to arrange on your own. Mondo Shared Tour is reported to be a good option if not wanting to organize the trip independently: https://www.sharedtours.com
Or you could be like us: we went on the Best of Italy tour a few years ago, and this year we're going on the South Italy tour. Best of both worlds!
We stayed in Sorrento last summer and did a wonderful Pompeii tour with Gaetano Manfredi (we saw him recommended on this site). He actually also arranged transportation for us (from/to Sorrento), as well as our requested hike up Vesuvius. I can’t recommend him enough. If you’re interested, I wrote a review of that day here: https://community.ricksteves.com/travel-forum/day-tours/amazing-pompeii-tour-with-gaetano-manfredi
Have a great trip!