Ramu Soma Pawar of Tusa was last week convicted by a local court and sentenced to life imprisonment for murder.
Police Sub Inspector of Thane Nagar Police Station S A Kakan said the incident took place yesterday when Pawar tried to hang himself using a rope made out of the bedsheet by the tree.
The other inmates rescued him and brought him back to the cell, Kakan said.
Following a complaint by the Jailor Vishal Bandal, a case under section 309 of the IPC (attempt to commit suicide) was registered and investigations are underway, police said.