my @countries = (
   "India",
   "America",
   "Germany",
   "Austria",
);

if ( grep { $_ eq $country } @countries ) {
   print "True";
}

##</code><code>##

my @countries = (
   "India",
   "America",
   "Germany",
   "Austria",
);

for (@countries) {
   if ($_ eq $country) {
      print "True";
      last;
   }
}

##</code><code>##

my @countries = (
   "India",
   "America",
   "Germany",
   "Austria",
);

my %countries = map { $_ => 1 } @countries;

if ($countries{$country}) {
   print "True";
}