Yes, you can file RTI Application to Directorate of Town and Country Planning (DTCP), Tamil Nadu.
The Govt. of Tamil Nadu enacted Town & Country Planning Act (T&CP Act), 1971 by repealing Town Planning Act 1920. DTCP functions under the control of Housing & Urban Development Department of the Secretariat. The department has its jurisdiction over the entire Tamil Nadu except Chennai Metropolitan Development Area (CMDA). DTCP is a "Public Authority" as per Section 2 (h) of the RTI Act 2005 and comes under its ambit.
You can file RTI to DTCP by addressing the same to the designated "Public Information Officer (PIO)" of the concerned Department of DTCP and by paying the prescribed fee. You can address the application either in English or Tamil Language.
To know more about the procedure o file RTI Applications in the State of Tamil Nadu, please refer https://onlinerti.com/how-to-file-rti-online-for-tamilnadu