Hii,The answer is yes.

Apply for lower branches (sciences,biotech,metallurgy,geology etc) in all old IITs.Give the order with importance to your wanted branch and their cutoffs by checking the previous year cutoffs.

You can also try giving options in new iits too,but possibility of getting core engineering branches is very low but not impossible.

If you are only interested in getting into IITs no matter what the branch is,then you are ok.But if you want to get a good branch specifically (like CS,Elec,Mech etc.),then I suggest to try again the next year.

There is also a branch option in the first year.If you have done exceptionally good in academics in your first semester,then you can apply for a branch change (for example from biotech to mech or chemical,or from naval architecture to aerospace) .The chances of getting a branch change is very low,but if you are determined enough ,then it is possible.I personally know people who got branch changes by becoming dead serious in acads in their first semester.Just to make you understand its difficulty,the CGPA cutoff for applying to CS branch was 9.8 during my first year,but a guy got branch change from biotech to chemical in my batch with around 8.6 CGPA.

Good luck.