"Yes and No" but not in the way one would normally think. Adcoms are not going to try to convert one's GPA based on some school calibre/ranking to even out the fields. That would be insane. They look at detailed transcripts from any school and your GMAT score (among other things) to make sure that evidence from one metric supports the other. For example, if you have a great GPA (3.5+), it should be supported by your GMAT score, etc. If you have a 3.8 GPA from some school but your GMAT is nowhere near the calibre of what 3.8 GPA should represent, then that will raise a flag.
Top schools are not filled with kids from Ivy leagues and other top schools. It's diverse and well represented from kids from various backgrounds.
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