Young people and senior citizens of the Maratha community waved saffron flags in a protest that the police said was free of incidents of violence, with more than 10,000 policemen on guard.
Traffic came to a halt in many parts of the business district, while protesters jammed suburban trains.
It was the concluding protest of a series of 57 marches last year across organised by the state's Maratha community to press its demands.
Rising unemployment and falling farm incomes are driving farming communities in several states to redouble calls for reservations in jobs and education.
"Farming is no longer profitable and jobs are not available," said one protester, Pradip Munde, a farmer from Osmanabad, a town more than 400 km southeast of Mumbai. "Reservation can ensure us better education and jobs."