AYINMOLLE Breathable Outdoor Vest with Hook and Loop attachment points, Olive Drab, One Size, Olive Drab, One Size

Q: can I fit a x2 taser in one of mag pouches

There are 3 pouches for a 30rd AR mag. Sure it will fit in one of those. The others seem to fit either double or single stack mags.

Q: How much weight can this vest hold?

I can’t give you a definitive top end weight but I think it’ll be fine with any style rifle plates, which usually weigh about 40lbs a pair. I would probably get a weight vest specifically for weight training if that was my purpose. The pocket for armor isn't really good for round training plates.