I want a new bike for daily commuting as well as long tours (4-5 inter-city or interstate trips per year). I’m confused between the Meteor 350, Himalayan 450, and the Royal Enfield Scrambler XC. Which one should I pick?

Of the options you've shortlisted, the Royal Enfield Himalayan 450 will be the best all-rounder with good highway manners, plush suspension for rough roads, and it's usable inside the city too, although its weight and general size need to be kept in mind. 

The Meteor 350 and Triumph Scrambler 400 XC will be better in the city than the Himalayan, but out on the highway, your comfortable cruising speeds will be capped at 80-100kph. Take a thorough test ride before you decide.