#!/usr/bin/perl

use strict;
use warnings;

my $in_file = '/path/to/in_file';
my $out_file= '/path/to/out_file';

open my $fh_in,'<',$in_file or die "$in_file: $!";
open my $fh_out,'>',$out_file or die "$out_file: $!";
while(my $line = <$fh_in>){
   $line =~ tr/,/\t/;
   print $fh_out $line;
}
close $fh_out;
close $fh_in;