Hi Rajendra,
Unfortunately, ACS 1113/ 4.2 doesn't support IPV6 and 1113 cannot be upgraded to ACS 5.x or 5.4 because it ( as a hardware) doesn't support linux. It's a windows based platform. However the ACS 4.2 database can be migrated on ACS 5.4 but on a different make of ACS - migration guide. ACS 5.x can be installed on ACS 1120,1121, 3415 etc and on vmware as well. ACS 5.4 does support IPV6 so your best bet is to install ACS 5.4 on a vmware and migrate the ACS 4.2 database.
~BR
Jatin Katyal
**Do rate helpful posts**
~Jatin