I have recieved many questions about TNPSC Departmental Exam Preparation. Since, the departmental exam is conducted for the working candidates all already working government staff might have known well about the departmental examination details. This information is to inform the new TNPSC appointed candidates as well as various TNPSC Group Jobs aspirants.
You can download the full study materials / books for the TNPSC Departmental Exam from the following link of TNPSC website.
All the best !