Hey Aditya! 

If, you clear the IIFT exam. The shortlisting process happens on the basis of your IIFT score, GD and PI. So, the top 160-170 will go to IIFT-Delhi. Next 160-170 to Kolkata Campus. So, you can change from Delhi to Kolkata Campus, in case you wish too. But, You can't change to the Delhi campus. As the whole process happens on the basis of your rank. And, just by filling the form for Delhi Campus, You are applicable for the rest. 

Please specify more your query like the programme & other information so that you can get answer of your query.

Good Luck!