Hi Ganesh,
I’m not aware of an out-of-the-box ‘range’ validator in version 11. So assuming this is a customization, I can imagine the configuration has been removed because the bootstrapping changed to yaml in version 12. Also the location of most validators changed from /hippo:configuration/hippo:frontend/cms/cms-validators to /hippo:configuration/hippo:modules/validation/hippo:moduleconfig. So you’ll have to redo the customization.
Jeroen