The pachyderm, which had come in search of water, trampled the boy identified as Vignesh, who was sleeping outside the house and flung him away.
Hearing his cries, his parents and brother rushed to help him, but were also attacked by the elephant, resulting in injuries to them.
The elephant then entered the house and damaged things there.
Police said animals from reserve forest area came to residential zones in search of water as check dams had dried up.