Hello yogesh! With 243 marks out of 400 in Nata 2019 you can get colleges like Capital College, NR school of Architecture, CIET in Coimbatore. In Chennai you can get Jaya school. And in the Dindigul district you can get Agni School and J. K. School of architecture. These were the Colleges with cut off under 243. 

Hope this helps. 

All the best!