The application process for TNSA is quite simple, candidate can simply apply using their website and then you will receive an e-mail comprising of the copy of your application in a PDF format. If your application gets selected, you will receive a call from TNSA representative who will confirm your application. At the end you just need to attend their counselling to ensure to your admission in TNSA !
In order to apply, you must have passed your class 10+2 in PCM (physics, chemistry, maths) stream with a minimum aggregate of 50% marks and you also need to pass their NATA exam ( national aptitude test in architecture).