Hey,

Its no where mentioned that if you appear for cat you won't  be able to appear iift or any other equivalent exams. You can appear for all other exams along with cat and have to fill the forms separately for other b-schools to wish to apply.

IIFT is a national-level management entrance exam conducted annually by National Testing Agency (NTA), for admission to its MBA (IB) program. IIFT 2020 will be conducted on December 1, 2019, in online or computer-based mode at around 18 exam centres across India. Around 75,000 candidates appeared for the exam the previous year.

For more information regarding iift exams visit the following website-

https://bschool.careers360.com/exams/iift

Hope this helps.