Right to manage
Flat owners have the collective right in some circumstances to take over the management of their block. This is a very techinical process.
This phrase simly means the right of flat owners to buy the freehold to their block as a group.
Many banks and mortgage companies will not lend moeny on a lease which has less than 60 years remaining. It is therefore important to extend your lease at the earliest possible opportunity as if dealt with before the lease reduced to 80 years the price paid could be significant lower than if you wait.