"The film seems to be trying to put a divide between Dalits and the others, " Athavale told.
The RPI chief's threat comes a day after the National Commission of Scheduled Castes (NCSC) also termed the film "anti- Dalit".
NCSC had earlier asked Prakash Jha to screen the film for a panel before its release Aug 12.
According to Athavale, the panel's chairman N.L. Punia wanted to ensure that the film does not misrepresent the constitutional stand and laws on reservation.
"But the screening did not take place. We will wait for the film to release and then protest against it if it promotes an anti-Dalit stand, " Athavale said.
"Aarakshan", starring Amitabh Bachchan, Saif Ali Khan and Deepika Padukone, is about reservations in the Indian education system. Khan plays a Dalit teacher.
The censor board has cleared the film with a U/A certificate.