The commemoration was organised by Saoradh, which is accused of having links with the New IRA.
he Parades Commission had ruled that no paramilitary-style clothing be worn in the procession.
The Unfinished Revolution National Easter Commemoration parade ended at Derry City Cemetery where an address was delivered.
Disturbances occurred outside the cemetery on Monday evening.
Police confirmed that officers had come under attack as they made arrests.
On Wednesday evening the PSNI said six men, arrested under the Terrorism Act as part of the investigation following the parade, have been released pending report to the Public Prosecution Service.
A PSNI spokesperson said: “The investigation will continue over the coming days and weeks to bring offenders to justice and officers would ask anyone with information about the incident or who may be able to help with the investigation to call police on the non-emergency number 101, or to submit a report online using the non-emergency reporting form via http://www.psni.police.uk/makeareport/. You can also contact Crimestoppers anonymously on 0800 555 111 or online at http://crimestoppers-uk.org/”
In total, seven men arrested under the Terrorism Act have been released pending reports to the PPS.
A 40-year-old man arrested on suspicion of disorderly behaviour and resisting police has been charged to appear at Londonderry Magistrates Court on May 11.