Did 6 million jews really die in the Holocaust?

Most of the victims were not shot or killed in the KZ. Most of them were killed by starvation. The Nazis ran out of food and thus tried to keep the supply solely for the German citizen. They targeted 2100 KCal for each grown up German, this only Non-Germans got, who worked in very important heavy jobs. Jews got from start of war only 700 KCal at best, this is the recommended intake of a 7kg Baby. This killed most of them, maybe not directly, but indirectly, as they collapsed during work or just died on one of the transports from A to B, when they basically got 0 food for days.

It's not far fetched, but from all historical estimations, this is indeed on the higher end.

First of all, the number 6 Million is not written in stone as a definite number, it is the accepted estimate and the true number, we will probably never know at this point. Methods used to acquire these numbers range from census counts and calculations to individual research to witness testimony.

There have been multiple noteworthy attempts to determine a precise estimation and from those "generally accepted", the estimations range from 5.1 to 6.2 Million, most of them coming to the conclusion of around 5.9 Million - hence "6 Million" is the accepted number used today (and for decades now).

People saying "6 Million Jews were murdered in the camps!" are wrong, however, as roughly 2 Million of them were murdered outside of such camps by other means.