Gandhi, who has been a vocal proponent for the nationwide enumeration, stated that he had sought details on the concrete framework and timeline for the exercise but received an "unsatisfactory response."
The proposal will take the overall quota to 75 per cent after including Centre's 10 per cent reservation for economically weaker section.
PM Modi's remarks came hours after the Bihar government released the data of its caste-based survey.
Senior advocate Shyam Divan, appearing on behalf of the Bihar government, submitted that the state required only 10 days to complete the process.
