It is very difficult to predict the JEE rank through AITS rank. AITS has quite lesser number of participants than JEE. As I am from FIITJEE, a rank under 100 in AITS is good, but it completely depends upon the no of students taking the exam which is quite low. Also a very good rank in AITS does not guarantee a good rank in JEE. One has to cover all the topics thoroughly for JEE. The previous years' JEE papers are the most important as solving them builds confidence and helps a lot.