Really at the end of the day you need to be in a caloric deficit to loose weight, keto, IF, they help but are "styles" that help you stay on track depending on how you are
IF is basically a plan that lets you eat gargantuan meals, if you're the type in life that likes to do everything go big or go home, it can work, but if not, it may not. Keto works for a minority of the population to be honest. Every coach swears by it because it "helps" (carbs bind to water, so dropping the carbs have you losing alot so it looks good, but its just water weight), if it works for you, then more power to you. Personally, me and most others, it has the same effect: tired, lethargic, terrible diarrhea, and acne problems. But if you happen to be of the minority that functions on it, it'll be a good diet.
Regardless, to lose weight, you need to be at a deficit, and more important, you have to accept that this is a longer journey and not a quick fast cycle. 10-15lbs, if its really in fat, will take between 7-15 weeks. Most are not able to handle 2lbs/week loss right off the bat, the deficit is very deep and alot crack within 2-5 weeks. Again, if you can do this, its great, but its best to start normal, then slowly escalade and build up.