retention views

Hello. What is the safest way to buy high retention views so video wont be taken down ( how much time after the video was uploaded , what number of views , over how many days) ?

It would be MUCH better if you simply opened a thread on the WTB section or Hire a Freelancer sections so members of BHW could send you their offers.
It's not allowed for anyone to try to sell you anything outside those sections of the forums.

Once you posted it this way you'll get suggestions from some people and offers from others.

There are some good providers on BST that can give you good high retention views, it's best to upload a video and see how it ranks giving it about 3k~ views if it ranks decently, just drip feed about 30k~ views over a 10 day period while building backlinks to a video. To lower chances of the video taken down, just give it a couple of weeks to get views naturally, get like 200-300 views, then boost it with views.