Yes, it is safe to use Vicks Babyrub on a 6-month-old baby based on the manufacturer's recommendation that it can be used from 3 months onwards. However, it is important to be careful around the baby's eyes and ensure it is only used externally. Babies may try to touch or put their hands in their mouth after application, so it's important to monitor their reaction. Additionally, babies' skin is delicate, so there is a small risk of a skin reaction. It is advisable to test a small area first before applying it more widely. While Vicks Babyrub may not be the first choice, it can be used with caution and following the precautions mentioned.