The TCICSTRN is the resource class name used by CICS to have its transactions protected by RACF. With CA Top secret the equivalent resource class name is OTRAN.
It means when CICS issues a RACROUTE call with TCICSTRN class, it's turned to OTRAN with TSS.
If customer has set SEC=YES, XTRAN=YES in the CICS SIT parameters or in the TSS/CICS facility FACMATRX=YES, EXTSEC=YES, XTRAN=YES then TCICSTRN
is active via OTRAN.
OTRAN is well documented within the TSS manuals.