About NATA -   NATA is National aptitude test in architecture. 10+2 or PUC students who   want to pursue a career in architecture will have to qualify NATA for   securing an admission in any of the architecture colleges in India.  NATA  is conducted by COA – Council of Architecture. Official site for  NATA  is www.nata.in
NATA is conducted through out the year and  students can take it any  time and date of their choice. However CET cell  of each state might  have a different date deadline for the submission  of the NATA scores to  them in order to qualify the aspirants for  counseling of B arch seats.  For example Karnataka CET cell has set May  15th as the last day for  receiving of NATA scores. So the students have  to be aware of this  deadline and plan to take NATA before the Specified  date by the  respective State CET cells.( note: individual NATA score are  announced 3  days after the student has taken the test)
NATA can  be taken any number of times in a year. This means if a  student gets  less score he can retake the test to improve his score by  re-registering  for the NATA by paying fees again. However NOT the best  score BUT the  average of the scores is taken into consideration. For  example a student  scores 80/200 marks in the first attempt and 110/200  marks in the  second attempt his over all score is (80+110)/2 = 95  marks. If in the  second attempt he managed to score only 50/200 then  his over all score  would get reduced to (80+50)/2 = 65. So it is always  better to prepare  well for the exam and get good scores in the first  attempt itself. NATA  scores are valid for 2 years.