They were arrested and booked after police scrutinised the CCTV footage and zeroed in on them after initially ascertaining the roles of 12 persons in the attack.
A official statement by the police said that initial investigations revealed that Mani, one of the six arrested, was a repeat offender and the police were were on his lookout in another case.
The two-wheeler used to commit the crime was seized, the statement said.
Two bike-borne men had hurled a lit kerosene-filled bottle at Teynampet Police station in the early hours on July 13, resulting in a fire, in which, however, no one was injured.