IELTS is not a substitute for the GMAT. There are schools that do not require the GMAT, but it makes no sense to attend them.

See: Why you should take the GMAT

PS new link -- https://find-mba.com/board/gmat/why-you-should-take-the-gmat-33542

I would strongly recommend you focus on January intake instead of September to get into a quality program and have better chances. Get the GMAT sorted and then look at European schools that have Jan intake such as IE, HEC, IMD, INSEAD and RSM. Most of these accept a few different language exams.

Does anybody know of a MBA program where I can submit an IELTS score instead of GMAT?

I would like to apply for fall admission but I do not have time to take the GMAT.

The IELTS just tests for English fluency. The GMAT is much more comprehensive, testing not only verbal English but also analytical and quantitative skills. It's important for business schools to know that you're capable of rigorous quantitative work and analyzing problems and data sets, because that's the kind of thing that MBA programs will include.

So to answer your question, no, I don't think there's a single accredited MBA program that will take an IELTS score as a substitute for GMAT score, because they test for entirely different things. You'd have more luck taking the GRE if you're somehow opposed to the GMAT.

Take the GMAT. There's really no reason not to.