I checked the Sky sports website and it says India vs New Zealand bilateral series will be covered by Sky Sports. So does that automatically mean it'll be available on NOW? Otherwise not sure if it's worth having a subscription.
If it's advertised on the Sky Sports Cricket channel or Main Event then it will be available on NOW with a monthly Sports Membership (not mobile Membership) or Day Sports Membership, unless there is a change to the schedule because the matches are cancelled due to Covid-19 for example.
If it was me i would wait until the day of the first match before buying the Membership and maybe check if your playback device or devices can support Bonus Streams just in case for some reason it is moved to the Sky Sports red button service due to an unforseen change on the Sky Sports schedule.