Hey mama! At 5 months, 6.3kg is actually quite normal for a breastfed baby, most babies around that age are anywhere from 5.5kg to 7kg depending on genetics and how they started, so your little one sounds right on track! A few of us moms in my circle have babies in that range din at 5 months, kaya don't worry. That said, if you're concerned or want to be sure, best to bring it up sa pedia during your next check-up so they can plot it on the growth chart and give you peace of mind, they'll tell you if there's anything to adjust with feeding. You're doing great, mama!