Hi Mahwish,
A very late answer, but this question still comes up a lot, so here’s where things stand.
IASSC doesn’t hand out the reference document ahead of time as a study file. According to IASSC’s permitted resources FAQ, the IASSC Reference Document is available as a download during the startup steps of your exam session, and you shouldn’t bring your own copy into the session. The same page lists which calculators are allowed. Graphing and programmable calculators, phone calculators and software like Minitab are not.
What that means for your revision: the formulas will be in front of you, but knowing which formula fits which situation won’t be. So practice choosing the tool. Work problems from a written description, without looking up which test or chart to use first.
My IASSC Lean Six Sigma Black Belt study guide page lists every topic on the exam with links to free articles. There’s a Green Belt version too.
Good luck with your revision, and ask here if a topic gives you trouble.
Ted