Chetram (40) was brought to a local court from district jail in connection with a case and lodged in the lock up where he tried to slit his throat, police said.
He was rushed to the district hospital in a critical condition, police said adding that a case has been registered in this connection.
SP (city) Sameer Saurabh said investigations are on to ascertain as to how the blade reached the inmate and how such an incident took place in police custody.