• Well, for one you do not link your file or file handle in any way to the declaration of the hash. How shall Perl know that you want to apply those expressions to the contents of your file?
• Also, regular expression matching is done using the m// operator or /regexp/. Nowhere you tell Perl that you expect matching.
• Thirdly, you need to use capture groups (...) in regular expressions to retrieve information.
• And then you need to loop some how over the lines of your file or apply the regexes repeatedly in some way.

If you put these points into action, it could look like the code below. I am reading from the DATA handle for convenience and read all lines into an unnamed array.

use strict;
use warnings;
my %hash = map { /(TCONS_00[0-9]+)\s+(XLOC_[0-9]+)/ } <DATA>;

my @keys= keys %hash;
my @values= values %hash;

print "@keys\n";
print "@values\n";
__DATA__
TCONS_00000047    XLOC_000039
TCONS_00000718    XLOC_000456
TCONS_00000938    XLOC_000610
TCONS_00004086    XLOC_002872
TCONS_00004252    XLOC_003003
TCONS_00004975    XLOC_003624
TCONS_00004976    XLOC_003624
TCONS_00005492    XLOC_004020
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