Hi Rahul ,
With 2400 you can get Metallurgy , Chem . Textile etc in old IIts also a duel course in civil IIT - M and IIT -KGP .
Apart from this you have a chance to get good branches in new IIT's Thus i wud suggest you to go for a new IIt as you wud have chance on Mech . ,Chem . ,Cs ,ECE there .
for more details check out below link
http://www.askiitians.com/iits-2009-2010-opening-and-closing-rank.aspx
Cutoff in new IITs check the link give below :
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 !!!!
Anshul