I am 24 yrs M. Still not crossed 50 kg in my whole life, my current weight is 48 how do I achieve 58

In order to gain mass (muscle), part of it is being in a caloric surplus (the amount depends on what your ultimate physique goal is) and the other part is lifting with a hypertrophy-centered program. There are some good examples of programs online that you can look up. As a beginner, a 3 days a week full body workout would be great for you.

Diet-wise, it is helpful to start by slowly increasing your calories gradually so you won't shock your body and feel so uncomfortable. Start with an increase of 100 calories above maintenance, and then I crease that amount after a couple of weeks after your body has adjusted. The liquid calories route is also helpful as things like protein shakes, smoothies, and olive oil are easier to digest. Make sure you are getting 1.4 to 2 grams of protein per kilogram of body weight. Don't fear carbs, as those are necessary to fuel your workouts. Be sure to also cut out sugar and processed crap as much as possible.

I hope that was a helpful starting point. You can do this.

Looks like the OP stayed for a week then never came back 🤷‍♂️

As someone who struggled with the same issue for a long time, I think you should get some blood tests done , check vit D levels, ferritine and blood cells count, these two made a huge difference ,once fixed I could reach and maintain weight easily, also reduce stress in your life , no more consuming cortizol triggering content or dealing with stressful situations and people, you should get in a peaceful state of mind where only the very important things get your attention( food, fun and studying), and then you'll have your appetit back and that 2500kcal will look like nothing🤣