There are several possibilities for burials in East London, it rather depends on when they occured and which religious group and denomination. Contact with Tower Hamlets and Newham Councils will tell you which cemeteries they manage.
The City of London Crematorium is probably the biggest in the area. Very close to that is a catholic cemetery. The Jewish cemetery is near Waltham Abbey. Many parish churches still have their own cemeteries .
if you have a specific individual in mind let us know the name and date and place of death and we can try to be more specific