7461070 : 12.1 : This utility requires the XML::Parser perl module
This thread should address your following issue -
R12.1.1 upgrade patch 7461070 Readme:
Source the Applications environment file
Run the Patch Application Assistant by entering "admsi.pl".
which give error:
This utility requires the XML::Parser perl module.
Please download and install XML::Parser from CPAN to run this utility.