Need urgent help: Production upgrade from 11.5.10 to R12.1.1 is hanging

All,
I need advise on the following.

We are doing production upgrade from 11.5.10 to R12.1.3.        All workers are hanging at following phase.

Worker  Code      Context            Filename                    Status
------  --------  -----------------  --------------------------  --------------
     1  Run       AutoPatch R120 pl  IGF3709292D.sql             Running
     2  Run       AutoPatch R120 pl  IGSSV3738488D.sql           Running
     3  Run       AutoPatch R120 pl  IGSFI3484209.sql            Running
     4  Run       AutoPatch R120 pl  IGSEN3888202.sql            Running
     5  Run       AutoPatch R120 pl  IGSSV3738488A.sql           Running
     6  Run       AutoPatch R120 pl  IGSSV4572862A.sql           Running
     7  Run       AutoPatch R120 pl  IGF4887473.sql              Running
     8  Run       AutoPatch R120 pl  IGSFI2566615.sql            Running
     9  Run       AutoPatch R120 pl  IGSPE2435520A.sql           Running