VERIFIED SOLUTION i
MapInfo Pro v17
A MapInfo Pro user is unable to find the 'Split Region' tool in MapInfo Pro v17.
The Split Region tool has developed over time from the previous version, the tool has now been re-modified and renamed.
ResolutionUPDATED: June 12, 2019
The tool within MapInfo Pro v17 has now been renamed from 'Split Regions' to 'Split Region using Polyline' and the new location is shown in the below screenshot.