I know you read the title, so let's just make one thing clear: there won't be six Power Rangers movies. The reboot Saban Entertainment hopes will be the launch of a massive franchise hits theaters this weekend, and there's a considerable amount of doubt over how it will do. The TV series was and still is a hugely successful property, but nostalgia acts like this have been hit or miss. For every 21 Jump Street there's a Jem and the Holograms, and we don't know where Power Rangers will land.
However, Haim Saban, the man who literally made Mighty Morphin Power Rangers happen, the plan is to follow-up this movie with five sequels that he hopes will form one gigantic tale. He tells Variety that "a six-movie story arc" is planned, but only if the first is successful.
There are multiple Power Rangers versions out there with different names, different Rangers, different locations, different powers. It's possible any sequels could pull from these rather than sticking with the current team. And maybe they will, but it won't be for six movies which is a rare feat.