The victim, identified as Ashok Murugan, died on the spot when the bus hit him at around 1.30 pm.
According to police, the victim was crossing the road along with his brother Suresh (12) and sister Laxmi (10) when the incident took place.
His siblings sustained injuries in the accident and were admitted to Rajawadi hospital in Ghatkopar.
The bus driver, identified as Jallaluddin Sheikh (25), was arrested for rash and negligent driving.
Residents of the area, where the accident took place, brought vehicular traffic on Ghatkopar-Andheri link road to a halt to protest against the "frequent" accidents taking place at the spot.