Hello Arpit,
Please check your instance profile if you have password rules define over there.
You can check below mentioned notes:
1. 1568362 - TMSADM password change
2. 761637 - Logon restrictions prevent TMSADM logon
Also check below mentioned link:
http://wiki.scn.sap.com/wiki/display/SL/Changing+the+TMSADM+password
I would suggest you delete the configuration in three systems and reconfigure as per note 761637. Please read this note carefully.
Rgds,
Sachin