Hi
Each store/core has its own data directory defined by
<dataDir>${data.dir.root}/${data.dir.store}</dataDir>
So it depends what is set for these properties.
See, for example, <SOLR>\workspace-SpacesStore\conf\solrcore.properties
If this turns out to be a relative path it will be in your default container directory for tomcat
Check the directory you delete looks like a SOLR index dir ….
Andy