Hi Parteek ,
congrats for your rank !!!!
with 864 in sc you can get in old IITs
Textile , metallurgy , Bio tech. Bio Chem , Mining ETC
whereas in New IITs you can get
CS, MECH. ,Civil .
thus you can get a good choice .
If you get a good rank in AIEEE and you get NIT's you can choose them over New IITs .For now i wud suggest you to wait for AIEEE results and only then decide .
for more details check out below links
http://www.askiitians.com/aieee-2010/aieee-2010-cut-offs.aspx
for details about NIT check the link below.
http://www.askiitians.com/aieee-counselling/aieee-engineering-counsellings.aspx
also
http://www.askiitians.com/aieee/AIEEE-Counselling
for IIT's
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