Actually it does work. Perhaps this is not your exact code, perhaps you just think it does not work. Perhaps you have <Name   > ie spaces after the token? If this is HTML or even if not s/<\s*name\s*>//ig may be better. Note you don't have a /g so will only do the first instance of <name> in a given string so perhaps that is your issue?

my @ary = qw[<name> <Name> <NaMe> ];
for (@ary) {
    print;
    s/<name>/japh!/i;
    print " $_\n";
}
__DATA__
<name> japh!
<Name> japh!
<NaMe> japh!
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