Rome Airport

It depends on your baggage and on the departure point of the flight to Rome. If you will be entering the Schengen area in Rome you'll need more time. Same if you must reclaim your baggage in Rome and check it again.

Which airline are you arriving with and from where (Schengen/Non Schengen)?
And which one are you flying to Verona? (I presume ITA?
If you are flying ITA to Rome from outside Schengen and connecting to an ITA flight to VRN, a couple of hours should be sufficient and you should be covered in case of delay as well (they'll book you in the next flight, although they only have a couple a day to Verona). Also in that case you don't need to worry about the checked luggage, because it will go straight to Verona and you don't need to retrieve anything.
If you take Neos Airline to Verona, then you probably need additional cushion, because I think you might need to retrieve the luggage and check it in again with Neos.

Is the Rome-Verona flight a separate booking or part of a single booking from whatever your origin is?

How much time you need depends on a lot of factors not mentioned in your question.

In one set of factors 75 minutes may be plenty; another set of factors may make 3 hrs a minimum 'safe' margin