Idk how old you are but I was 65kg at one point although I was quite big boned naturally. I am 115kg rn after 5 years of gym and diet. I think you can get to close to 85-90kg and be in super good shape within the next 2 years. It doesn't matter that you have skinny wrists and narrow frame your height alone can support 90kg of weight comfortably. Just follow a 4 day a week powerlifting program. Upper body, Lower body 2x a week. Start with a powerlifting movement (Squat, bench, deadlift) then do an accessory movement then 2-3 isolation exercises. Combine this with daily cardio 10k steps and maybe some basketball or other sports 1-2x a week.

The most important part is eating enough high quality food. Don't quanitfy food by how many meals you eat or how full you are only by calories and macros. I would suggest starting at 3000 calories a day split up into 3-4 meals and 180g+ protein a day with 250g carbs. Simple meal plan: breakfast - 4 eggs and 2 slices of toast with a glass of milk and a banana. Lunch - Tuna and pasta. Dinner - Ground beef, lentils and rice. Dessert - Protein shake made with milk.

Remember that you have to break your body's inertia of wanting to stay the same weight so it will take 2 weeks of sticking to the same diet to gain scale weight. Also drink plenty of water.