DTCP means Directorate of Town & Country Planning. Except in chennai metropolitan area where CMDA is approving the layouts of housing, Institutional & Industrial layouts beyond 1 hectare extents all other places in Tamilnadu DTCP is the authority to approve such developments.
The CMDA (Chennai Metropolitan Development Authority) appraisal of the land you are about to buy is within the city limits. If you are buying from Residential promoters, Ask for their layout map and see if there is a CMDA Approval Number. It is legally permitted.
Planning permission or developmental approval refers to the approval needed for construction or expansion (including significant renovation) in some jurisdictions. It is usually given in the form of a building permit (or construction permit). ... House building permits.