Please tell which is better old or new IIT. Please also tell which are 3 best new IIT

Hi , 

There is no comparison in old and new IITs .. Old IITs are very old and very established.. New IITs are under the mentorship of old IITs .. And it will take time but the new IIT's will become the equaly good as old iit in terms of eduction, infrastructure and placement..

For more details ... please click the links given below:

Check out the opening and closing rank :
http://www.askiitians.com/iits-2009-2010-opening-and-closing-rank.aspx

for cutoff in new IITs  check the link

http://jee.iitd.ac.in/openclose09.htm    (this link includes the more detail analysis)

for code of the cources check the councelling broucher 2009.

All the best !!