Well, I thought spoiler-filled movie trailers were a recent scourge, but apparently they've been around a few decades.
Kerr is sent to the Himalayas - possibly India,, as Calcutta seems to be the nearest postal site - to oversee a convent. There's inappropriate sexual tension between several of the nuns, including Kerr, and the local British handyman/translator. Somebody goes psycho, as you might guess from the above.
There are plenty of places you could take offense at this film. In fact it seems never to have met a cultural or gender stereotype it didn't like. But you'd be missing the point. This movie is batshit insane! Just giving into the sensual experience is the best way to appreciate it. It's a massive head trip.