The criteria for being "highly cited" to pass WP:PROF#C1 varies between fields. This page is an effort to compile general h-index cutoffs for those fields, noting that not meeting the general cutoff does not necessarily mean that the person doesn't meet other notability criteria.
based on library holdings
"(1) more than a few hundred citations, (2) h-index more than 10-15, (3) book(s) held by lots of institutions, (4) major discovery, etc"