Police said the victims, all Pune residents, were returning after attending a friend's wedding in Ahmednagar district.
"The accident took place near Lonikand when a water- tanker collided with the bus," said an official of Lonikand police station.
The deceased were identified as Vaibhav Mane (27), Mahesh Pawar (28), Nupur Sahu (26), Nikhil Jadhav (26), Akshay Dabhade (28) and Vishal Chavan (29).
The injured were rushed to private hospitals in Wagholi near Pune.