Upon viewing his portfolio at the link you provided, my first thought was push processing. In push processing, one typically underexposes the shot (that is, meters and set exposure as if the the film were a higher ISO than it really is), then compensate in the darkroom by overdeveloping the film to account for the underexposed shot.

Push processing tends to increase the contrast of the photo, as well as increase the film grain, making it appear very grainy or "noisy". Renato's portfolio certainly shows this.

D'Agostin appears to do all of his work in the darkroom, rather than scanning film and editing in post/Photoshop. For instance, in this interview with D'Agostin by bestkeptsecretsintheworld.com, Renato says (emphasis mine),

Actually, I quit after two months the Photography-school in Milano. It was not for me, so I started to be Photographers Assistant where I spend a lot of time in the darkroom.

Your work is still analogue and hand-printed black & white Photography with lots of grains in it. Which camera and film do you use?

A Leica M6, which is very small and easy to carry around. Film, basically everything I can find, but I prefer Kodak Tri-X400.

[re: digital photography,]

No, I’m not interested in Digital photography. I can’t stay behind a computer for many hours. It’s not natural for me. I want to use my time and skills in what I love doing.

In this 2017 interview with MAPS-mag.com, he clearly indicates his preference for film and darkroom processing (emphasis also mine):

Which film do you prefer to take b/w photo?

I mostly use Kodak Tri-x 400. Sometimes Ilford 3200, it depends on the project. And sometimes whatever I find. I’m not very technical, as I believe in the photographic result rather than the way I got there or what I’ve used.

Do you print film by yourself?

I process film by myself, and then print the photographs in my darkroom, which has become an essential part of my life.

What is the most important for you?

My lonely moment in the darkroom thinking about what my photography is and what I want it to be.

D'Agostin's images are certainly stylized for, and emphasize the results of, push processing. He also prints very large – I saw somewhere he moved to a studio darkroom where he could print at over 2 meters, from 35mm film — which would also overemphasize film grain when viewed at typical poster print size viewing distances. So that's certainly his style, especially in conjunction with his use of uncluttered subject framing and long-focal-length lens to isolate the subject from its environment.

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With regards to emulating his style using your DSLR, realize that the digital "equivalent" of the darkroom is Photoshop (or its alternatives). To the extent that you're trying to copy his style, your camera settings don't really matter that much. That is, you have a lot of leeway to lose image information – increasing contrast, adding grain, converting to B&W, etc. – from an otherwise well-exposed image. His darkroom style lends itself to relatively easy emulation in Photoshop, turning digital captures that might be suboptimally exposed into D'Agostin-esque art in the digital darkroom.

I don't mean to belittle his style — I quite like his portfolio. And judging from the esteemed galleries that show his art, it seems to be well-regarding. But with regards to emulating the style digitally, it's a very forgiving process in post-processing, not requiring a lot of technique in the capture per se. (Notwithstanding the art of composition, regardless).